$y(x)= x^2 - 6x + 22.09$ tangent [closed]

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$$y(x)= x^2-6x+22.09$$
I need to find the exact points where the tangents that pass through $0$, touch the curve using the first derivative. Any help would be great.
calculus functions derivatives tangent-line
closed as off-topic by Adrian Keister, amWhy, Leucippus, max_zorn, HK Lee Aug 31 at 1:40
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." â Adrian Keister, amWhy, Leucippus, max_zorn, HK Lee
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up vote
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$$y(x)= x^2-6x+22.09$$
I need to find the exact points where the tangents that pass through $0$, touch the curve using the first derivative. Any help would be great.
calculus functions derivatives tangent-line
closed as off-topic by Adrian Keister, amWhy, Leucippus, max_zorn, HK Lee Aug 31 at 1:40
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." â Adrian Keister, amWhy, Leucippus, max_zorn, HK Lee
Do you mean the points of tangency? The question reads like you want the intersections between the tangents, but that $(0,0)$ so I know it isn't what you mean. For the points where the tangent lines touch the parabola, correct?
â saulspatz
Aug 30 at 1:09
yeah (0,0) is already the point where tangents intersect Question is ambiguous
â Deepesh Meena
Aug 30 at 1:13
yep, i meant the points where the where the tangents touch the parabola
â maths noob
Aug 30 at 1:33
add a comment |Â
up vote
0
down vote
favorite
up vote
0
down vote
favorite
$$y(x)= x^2-6x+22.09$$
I need to find the exact points where the tangents that pass through $0$, touch the curve using the first derivative. Any help would be great.
calculus functions derivatives tangent-line
$$y(x)= x^2-6x+22.09$$
I need to find the exact points where the tangents that pass through $0$, touch the curve using the first derivative. Any help would be great.
calculus functions derivatives tangent-line
calculus functions derivatives tangent-line
edited Aug 30 at 2:18
Rafael Holanda
2,485522
2,485522
asked Aug 30 at 0:41
maths noob
63
63
closed as off-topic by Adrian Keister, amWhy, Leucippus, max_zorn, HK Lee Aug 31 at 1:40
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." â Adrian Keister, amWhy, Leucippus, max_zorn, HK Lee
closed as off-topic by Adrian Keister, amWhy, Leucippus, max_zorn, HK Lee Aug 31 at 1:40
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." â Adrian Keister, amWhy, Leucippus, max_zorn, HK Lee
Do you mean the points of tangency? The question reads like you want the intersections between the tangents, but that $(0,0)$ so I know it isn't what you mean. For the points where the tangent lines touch the parabola, correct?
â saulspatz
Aug 30 at 1:09
yeah (0,0) is already the point where tangents intersect Question is ambiguous
â Deepesh Meena
Aug 30 at 1:13
yep, i meant the points where the where the tangents touch the parabola
â maths noob
Aug 30 at 1:33
add a comment |Â
Do you mean the points of tangency? The question reads like you want the intersections between the tangents, but that $(0,0)$ so I know it isn't what you mean. For the points where the tangent lines touch the parabola, correct?
â saulspatz
Aug 30 at 1:09
yeah (0,0) is already the point where tangents intersect Question is ambiguous
â Deepesh Meena
Aug 30 at 1:13
yep, i meant the points where the where the tangents touch the parabola
â maths noob
Aug 30 at 1:33
Do you mean the points of tangency? The question reads like you want the intersections between the tangents, but that $(0,0)$ so I know it isn't what you mean. For the points where the tangent lines touch the parabola, correct?
â saulspatz
Aug 30 at 1:09
Do you mean the points of tangency? The question reads like you want the intersections between the tangents, but that $(0,0)$ so I know it isn't what you mean. For the points where the tangent lines touch the parabola, correct?
â saulspatz
Aug 30 at 1:09
yeah (0,0) is already the point where tangents intersect Question is ambiguous
â Deepesh Meena
Aug 30 at 1:13
yeah (0,0) is already the point where tangents intersect Question is ambiguous
â Deepesh Meena
Aug 30 at 1:13
yep, i meant the points where the where the tangents touch the parabola
â maths noob
Aug 30 at 1:33
yep, i meant the points where the where the tangents touch the parabola
â maths noob
Aug 30 at 1:33
add a comment |Â
3 Answers
3
active
oldest
votes
up vote
0
down vote
accepted
This is the parabola and the two tangent lines that pass through $(0,0)$:

In order to find the two tangent lines, let's consider the line equation in the slope-intercept form:
$$
y = ax + b
$$
Since both lines pass through $(0,0)$ we can easily deduct that $b=0$, so we have:
$$
y = ax
$$
In that equation, $a$ is the slope of the tangent line, which means it is its derivative:
$$
a = cfracdydx = 2x - 6
$$
So now we have a line equation that looks like this:
$$
y = ax = (2x - 6)x = 2x^2 - 6x
$$
Let's consider a point that passes through the parabola equation: $(x, x^2 - 6x + 22.09)$. Let's substitute this point in the tangent line equation:
$$
2x^2 - 6x = x^2 - 6x + 22.09 \
x^2 = 22.09 \
x = pm4.7
$$
Finally we have:
$y = 2x^2 - 6x rightarrow y = 2(4.7)^2 - 6(4.7) rightarrow y = 15.98$
$y = 2x^2 - 6x rightarrow y = 2(-4.7)^2 - 6(-4.7) rightarrow y = 72.38$
So the tangent lines intercept the parabola in the points $(4.7, 15.98)$ and $(-4.7, 72.38)$
add a comment |Â
up vote
0
down vote
Assuming I'm correct about what you are asking (see my comment), here is an outline of what you need to do. Pick some point $(x_0,y_0)$ on the curve an assume that the tangent to the curve at that point passes through $(0,0).$ Note that you are really only picking $x_0$ because once you've chosen $x_0$ that value of $y_0$ is determined. Now we knoe a point on the tangent line, namely $(x_0,y_0)$ and we know then slope, namely $y'(x_0).$
That gives you the equation of the tangent line, so you just need to see what condition ob $x_0$ will force $(0,0)$ to lie on the line. That's easy; just assume $(0,0)$ satisfies the equation, and see what that tells you about $x_0$. Check to be sure that the steps are reversible.
yes you are correct, I meant the points where the tangents touch the parabola
â maths noob
Aug 30 at 1:25
add a comment |Â
up vote
0
down vote
Let the equation of the tangent line be $y=mx$
The line and the parabola intersect where we have $$x^2-6x+22.09= mx$$double root.
That is $$x^2-(m+6)x+22.09=0$$ has double roots.
We need $$(m+6)^2-4(22.09)=0$$ which gives us$$ m=-6pm sqrt 22.09 =-6pm 4.7$$
For each of these slopes you find the intersection of $y=mx$ and your parabola.
this is $$ ??what?
â Deepesh Meena
Aug 30 at 1:21
1
I had to leave my mobile device , so I finished my solution later. Sorry for causing confusion. You can check the answer now.
â Mohammad Riazi-Kermani
Aug 30 at 1:29
Thanks Mohammad, very helpful
â maths noob
Aug 30 at 3:00
add a comment |Â
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
accepted
This is the parabola and the two tangent lines that pass through $(0,0)$:

In order to find the two tangent lines, let's consider the line equation in the slope-intercept form:
$$
y = ax + b
$$
Since both lines pass through $(0,0)$ we can easily deduct that $b=0$, so we have:
$$
y = ax
$$
In that equation, $a$ is the slope of the tangent line, which means it is its derivative:
$$
a = cfracdydx = 2x - 6
$$
So now we have a line equation that looks like this:
$$
y = ax = (2x - 6)x = 2x^2 - 6x
$$
Let's consider a point that passes through the parabola equation: $(x, x^2 - 6x + 22.09)$. Let's substitute this point in the tangent line equation:
$$
2x^2 - 6x = x^2 - 6x + 22.09 \
x^2 = 22.09 \
x = pm4.7
$$
Finally we have:
$y = 2x^2 - 6x rightarrow y = 2(4.7)^2 - 6(4.7) rightarrow y = 15.98$
$y = 2x^2 - 6x rightarrow y = 2(-4.7)^2 - 6(-4.7) rightarrow y = 72.38$
So the tangent lines intercept the parabola in the points $(4.7, 15.98)$ and $(-4.7, 72.38)$
add a comment |Â
up vote
0
down vote
accepted
This is the parabola and the two tangent lines that pass through $(0,0)$:

In order to find the two tangent lines, let's consider the line equation in the slope-intercept form:
$$
y = ax + b
$$
Since both lines pass through $(0,0)$ we can easily deduct that $b=0$, so we have:
$$
y = ax
$$
In that equation, $a$ is the slope of the tangent line, which means it is its derivative:
$$
a = cfracdydx = 2x - 6
$$
So now we have a line equation that looks like this:
$$
y = ax = (2x - 6)x = 2x^2 - 6x
$$
Let's consider a point that passes through the parabola equation: $(x, x^2 - 6x + 22.09)$. Let's substitute this point in the tangent line equation:
$$
2x^2 - 6x = x^2 - 6x + 22.09 \
x^2 = 22.09 \
x = pm4.7
$$
Finally we have:
$y = 2x^2 - 6x rightarrow y = 2(4.7)^2 - 6(4.7) rightarrow y = 15.98$
$y = 2x^2 - 6x rightarrow y = 2(-4.7)^2 - 6(-4.7) rightarrow y = 72.38$
So the tangent lines intercept the parabola in the points $(4.7, 15.98)$ and $(-4.7, 72.38)$
add a comment |Â
up vote
0
down vote
accepted
up vote
0
down vote
accepted
This is the parabola and the two tangent lines that pass through $(0,0)$:

In order to find the two tangent lines, let's consider the line equation in the slope-intercept form:
$$
y = ax + b
$$
Since both lines pass through $(0,0)$ we can easily deduct that $b=0$, so we have:
$$
y = ax
$$
In that equation, $a$ is the slope of the tangent line, which means it is its derivative:
$$
a = cfracdydx = 2x - 6
$$
So now we have a line equation that looks like this:
$$
y = ax = (2x - 6)x = 2x^2 - 6x
$$
Let's consider a point that passes through the parabola equation: $(x, x^2 - 6x + 22.09)$. Let's substitute this point in the tangent line equation:
$$
2x^2 - 6x = x^2 - 6x + 22.09 \
x^2 = 22.09 \
x = pm4.7
$$
Finally we have:
$y = 2x^2 - 6x rightarrow y = 2(4.7)^2 - 6(4.7) rightarrow y = 15.98$
$y = 2x^2 - 6x rightarrow y = 2(-4.7)^2 - 6(-4.7) rightarrow y = 72.38$
So the tangent lines intercept the parabola in the points $(4.7, 15.98)$ and $(-4.7, 72.38)$
This is the parabola and the two tangent lines that pass through $(0,0)$:

In order to find the two tangent lines, let's consider the line equation in the slope-intercept form:
$$
y = ax + b
$$
Since both lines pass through $(0,0)$ we can easily deduct that $b=0$, so we have:
$$
y = ax
$$
In that equation, $a$ is the slope of the tangent line, which means it is its derivative:
$$
a = cfracdydx = 2x - 6
$$
So now we have a line equation that looks like this:
$$
y = ax = (2x - 6)x = 2x^2 - 6x
$$
Let's consider a point that passes through the parabola equation: $(x, x^2 - 6x + 22.09)$. Let's substitute this point in the tangent line equation:
$$
2x^2 - 6x = x^2 - 6x + 22.09 \
x^2 = 22.09 \
x = pm4.7
$$
Finally we have:
$y = 2x^2 - 6x rightarrow y = 2(4.7)^2 - 6(4.7) rightarrow y = 15.98$
$y = 2x^2 - 6x rightarrow y = 2(-4.7)^2 - 6(-4.7) rightarrow y = 72.38$
So the tangent lines intercept the parabola in the points $(4.7, 15.98)$ and $(-4.7, 72.38)$
edited Aug 30 at 2:51
answered Aug 30 at 2:45
HugoTeixeira
256211
256211
add a comment |Â
add a comment |Â
up vote
0
down vote
Assuming I'm correct about what you are asking (see my comment), here is an outline of what you need to do. Pick some point $(x_0,y_0)$ on the curve an assume that the tangent to the curve at that point passes through $(0,0).$ Note that you are really only picking $x_0$ because once you've chosen $x_0$ that value of $y_0$ is determined. Now we knoe a point on the tangent line, namely $(x_0,y_0)$ and we know then slope, namely $y'(x_0).$
That gives you the equation of the tangent line, so you just need to see what condition ob $x_0$ will force $(0,0)$ to lie on the line. That's easy; just assume $(0,0)$ satisfies the equation, and see what that tells you about $x_0$. Check to be sure that the steps are reversible.
yes you are correct, I meant the points where the tangents touch the parabola
â maths noob
Aug 30 at 1:25
add a comment |Â
up vote
0
down vote
Assuming I'm correct about what you are asking (see my comment), here is an outline of what you need to do. Pick some point $(x_0,y_0)$ on the curve an assume that the tangent to the curve at that point passes through $(0,0).$ Note that you are really only picking $x_0$ because once you've chosen $x_0$ that value of $y_0$ is determined. Now we knoe a point on the tangent line, namely $(x_0,y_0)$ and we know then slope, namely $y'(x_0).$
That gives you the equation of the tangent line, so you just need to see what condition ob $x_0$ will force $(0,0)$ to lie on the line. That's easy; just assume $(0,0)$ satisfies the equation, and see what that tells you about $x_0$. Check to be sure that the steps are reversible.
yes you are correct, I meant the points where the tangents touch the parabola
â maths noob
Aug 30 at 1:25
add a comment |Â
up vote
0
down vote
up vote
0
down vote
Assuming I'm correct about what you are asking (see my comment), here is an outline of what you need to do. Pick some point $(x_0,y_0)$ on the curve an assume that the tangent to the curve at that point passes through $(0,0).$ Note that you are really only picking $x_0$ because once you've chosen $x_0$ that value of $y_0$ is determined. Now we knoe a point on the tangent line, namely $(x_0,y_0)$ and we know then slope, namely $y'(x_0).$
That gives you the equation of the tangent line, so you just need to see what condition ob $x_0$ will force $(0,0)$ to lie on the line. That's easy; just assume $(0,0)$ satisfies the equation, and see what that tells you about $x_0$. Check to be sure that the steps are reversible.
Assuming I'm correct about what you are asking (see my comment), here is an outline of what you need to do. Pick some point $(x_0,y_0)$ on the curve an assume that the tangent to the curve at that point passes through $(0,0).$ Note that you are really only picking $x_0$ because once you've chosen $x_0$ that value of $y_0$ is determined. Now we knoe a point on the tangent line, namely $(x_0,y_0)$ and we know then slope, namely $y'(x_0).$
That gives you the equation of the tangent line, so you just need to see what condition ob $x_0$ will force $(0,0)$ to lie on the line. That's easy; just assume $(0,0)$ satisfies the equation, and see what that tells you about $x_0$. Check to be sure that the steps are reversible.
answered Aug 30 at 1:17
saulspatz
11.4k21324
11.4k21324
yes you are correct, I meant the points where the tangents touch the parabola
â maths noob
Aug 30 at 1:25
add a comment |Â
yes you are correct, I meant the points where the tangents touch the parabola
â maths noob
Aug 30 at 1:25
yes you are correct, I meant the points where the tangents touch the parabola
â maths noob
Aug 30 at 1:25
yes you are correct, I meant the points where the tangents touch the parabola
â maths noob
Aug 30 at 1:25
add a comment |Â
up vote
0
down vote
Let the equation of the tangent line be $y=mx$
The line and the parabola intersect where we have $$x^2-6x+22.09= mx$$double root.
That is $$x^2-(m+6)x+22.09=0$$ has double roots.
We need $$(m+6)^2-4(22.09)=0$$ which gives us$$ m=-6pm sqrt 22.09 =-6pm 4.7$$
For each of these slopes you find the intersection of $y=mx$ and your parabola.
this is $$ ??what?
â Deepesh Meena
Aug 30 at 1:21
1
I had to leave my mobile device , so I finished my solution later. Sorry for causing confusion. You can check the answer now.
â Mohammad Riazi-Kermani
Aug 30 at 1:29
Thanks Mohammad, very helpful
â maths noob
Aug 30 at 3:00
add a comment |Â
up vote
0
down vote
Let the equation of the tangent line be $y=mx$
The line and the parabola intersect where we have $$x^2-6x+22.09= mx$$double root.
That is $$x^2-(m+6)x+22.09=0$$ has double roots.
We need $$(m+6)^2-4(22.09)=0$$ which gives us$$ m=-6pm sqrt 22.09 =-6pm 4.7$$
For each of these slopes you find the intersection of $y=mx$ and your parabola.
this is $$ ??what?
â Deepesh Meena
Aug 30 at 1:21
1
I had to leave my mobile device , so I finished my solution later. Sorry for causing confusion. You can check the answer now.
â Mohammad Riazi-Kermani
Aug 30 at 1:29
Thanks Mohammad, very helpful
â maths noob
Aug 30 at 3:00
add a comment |Â
up vote
0
down vote
up vote
0
down vote
Let the equation of the tangent line be $y=mx$
The line and the parabola intersect where we have $$x^2-6x+22.09= mx$$double root.
That is $$x^2-(m+6)x+22.09=0$$ has double roots.
We need $$(m+6)^2-4(22.09)=0$$ which gives us$$ m=-6pm sqrt 22.09 =-6pm 4.7$$
For each of these slopes you find the intersection of $y=mx$ and your parabola.
Let the equation of the tangent line be $y=mx$
The line and the parabola intersect where we have $$x^2-6x+22.09= mx$$double root.
That is $$x^2-(m+6)x+22.09=0$$ has double roots.
We need $$(m+6)^2-4(22.09)=0$$ which gives us$$ m=-6pm sqrt 22.09 =-6pm 4.7$$
For each of these slopes you find the intersection of $y=mx$ and your parabola.
edited Aug 30 at 1:27
answered Aug 30 at 1:20
Mohammad Riazi-Kermani
31k41853
31k41853
this is $$ ??what?
â Deepesh Meena
Aug 30 at 1:21
1
I had to leave my mobile device , so I finished my solution later. Sorry for causing confusion. You can check the answer now.
â Mohammad Riazi-Kermani
Aug 30 at 1:29
Thanks Mohammad, very helpful
â maths noob
Aug 30 at 3:00
add a comment |Â
this is $$ ??what?
â Deepesh Meena
Aug 30 at 1:21
1
I had to leave my mobile device , so I finished my solution later. Sorry for causing confusion. You can check the answer now.
â Mohammad Riazi-Kermani
Aug 30 at 1:29
Thanks Mohammad, very helpful
â maths noob
Aug 30 at 3:00
this is $$ ??what?
â Deepesh Meena
Aug 30 at 1:21
this is $$ ??what?
â Deepesh Meena
Aug 30 at 1:21
1
1
I had to leave my mobile device , so I finished my solution later. Sorry for causing confusion. You can check the answer now.
â Mohammad Riazi-Kermani
Aug 30 at 1:29
I had to leave my mobile device , so I finished my solution later. Sorry for causing confusion. You can check the answer now.
â Mohammad Riazi-Kermani
Aug 30 at 1:29
Thanks Mohammad, very helpful
â maths noob
Aug 30 at 3:00
Thanks Mohammad, very helpful
â maths noob
Aug 30 at 3:00
add a comment |Â
Do you mean the points of tangency? The question reads like you want the intersections between the tangents, but that $(0,0)$ so I know it isn't what you mean. For the points where the tangent lines touch the parabola, correct?
â saulspatz
Aug 30 at 1:09
yeah (0,0) is already the point where tangents intersect Question is ambiguous
â Deepesh Meena
Aug 30 at 1:13
yep, i meant the points where the where the tangents touch the parabola
â maths noob
Aug 30 at 1:33