How to Find Tangent Lines to Y=x^2 Passing Through (2,3) [SOLVED] Tangent Line

In summary, the problem is to find all tangent lines to the graph Y=x^2 that pass through the point (2,3). The first attempt was to find the derivative of the equation, y' = 2x, and plug in x=2, but it was realized that this is not the correct point to use. The correct approach is to use the slope and the given point to find the equation of the tangent line.
  • #1
physstudent1
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[SOLVED] Tangent Line

Homework Statement


Find all tangent lines that are tangent to Y=x^2 and go through the point (2,3)


Homework Equations





The Attempt at a Solution



At first I thought I knew how to do this problem, I found the derivative of the equation got:

y' = 2x ; then I plugged in x=2 to find the slope of the tangent however then i realized this is not the correct point to plug in because this is not the point that the line is actually going to be hitting the original graph at; I don't know how you would find this said point to plug in for x to get the slope can anyone steer me in the right direction
 
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  • #2
You are looking for a line. You have the slope, and a point that the line goes through. That's sufficient information to derive the line equation.
 
  • #3
I don't have the slope though because I don't know what point the line is tangent to on the curve so how can i plug a value into the derivative to get slope
 
  • #4
y' = 2x is the family of all lines that are tangent to x^2. You are supposed to find the one that goes through (2,3).
 
  • #5
oh i see thank you for your help :)
 

1. What is a tangent line?

A tangent line is a straight line that touches a curve at only one point and has the same slope as the curve at that point.

2. How do I find the equation of a tangent line?

To find the equation of a tangent line, you will need to use the derivative at the point of tangency. First, find the derivative of the function, plug in the x-coordinate of the point of tangency to find the slope, and then use the point-slope formula to find the equation of the tangent line.

3. What does the point (2,3) represent in this problem?

The point (2,3) represents the point of tangency between the tangent line and the curve.

4. Can I use this method to find tangent lines to any type of curve?

Yes, this method can be used to find tangent lines to any type of curve, as long as the curve is differentiable at the point of tangency.

5. Is there an alternative method for finding tangent lines?

Yes, another method for finding tangent lines is to use the slope-intercept form of a line and set the slope equal to the derivative of the function at the point of tangency. This will give you the y-intercept, and you can then use the point-slope formula to find the equation of the tangent line.

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