Tangent Lines to f(x)=x^2-4x+5 Through P(0,1)

In summary, to find the equation for two lines that are tangent to the graph of f(x)=x^2-4x+5 and pass through the point P(0,1), we can use the derivative, f'(x)=2x-4, to find the slope of the tangent line at x=0. Then, we can use the point-slope form or the general line equation to find the equation for the tangent line.
  • #1
Weave
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Homework Statement


Given: [tex]f(x)=x^2-4x+5[/tex] find equation for two lines that are tangent to the graph and pass through the point P(0,1)

Homework Equations


[tex]f(x)=x^2-4x+5[/tex]
[tex]\frac{dy}{dx}=2x-4[/tex]
Equation of the tangent line/s
[tex] f(x)=f'(a)(x-a)+f(a)[/tex]

The Attempt at a Solution


Just need to get started
 
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  • #2
You seem to have everything you need. You have the derivative, which gives you the slope of the tangent line at any point you plug in. You're supposed to find the tangent line at the point (0, 1), which means you need the slope at x=0. You can use point-slope form to find the line equation if you want, or you can literally just plug the numbers into the general line equation you were given.

- Warren
 
  • #3
lol... revelation I got it.
Don't you love it when you make things more complicated then they need to be?:rofl:
 

1. What is a tangent line?

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

2. How do you find the slope of a tangent line?

The slope of a tangent line can be found by taking the derivative of the function at the point of tangency. In this case, the function is f(x) = x^2-4x+5, so the derivative is f'(x) = 2x-4. Plug in the x coordinate of the point of tangency (in this case, 0) to find the slope.

3. What is the equation of the tangent line to f(x) = x^2-4x+5 at P(0,1)?

The equation of a tangent line can be written in point-slope form: y - y1 = m(x - x1), where m is the slope and (x1,y1) is the point of tangency. Plug in the slope (found in the previous question) and the coordinates of P(0,1) to get the equation y - 1 = -4x. Simplify to get the final equation of the tangent line: y = -4x + 1.

4. How does the slope of the tangent line change as the point of tangency moves?

The slope of the tangent line changes as the point of tangency moves because the derivative of the function changes at different points. This means that the slope of the tangent line is not constant and will vary depending on the location of the point of tangency.

5. Can there be more than one tangent line to a curve at a given point?

No, there can only be one tangent line to a curve at a given point. This is because a tangent line is defined as a line that touches the curve at only one point, so there cannot be multiple lines that satisfy this condition at the same point.

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