How do you find the equation of a line tangent to the function y=x32x2+2 at (2,2)?

1 Answer
May 19, 2017

y=4x6

Explanation:

First, find the derivative of y, which is

y=3x24x

Now, plug in the x-value (2) into this equation to find the slope of the tangent line:

y=3(2)24(2)=4

Now plug the x-value (2) back into the original equation to find the y-coordinate of the tangential point:

y=(2)32(2)2+2=2

(Technically I didn't need to do this since the y-coordinate was given; I did it anyway so you could find the tangent line with just a given x-coordinate.)

Lastly, use the point-slope formula to find the equation of the line tangent to the function at x=2:

yy1=m(xx1)

y2=4(x2)

y=4x6