How do you find the equation of the line tangent to the curve y=x^3y=x3 at the point (-1,-1)?

1 Answer
Apr 27, 2015

First you evaluate the derivative of your function y'(x):
Then you evaluate the derivative at x_0=-1, or y'(-1), which is the slope m of your tangent line.
Finally find the equation of the line using:
y-y_0=m(x-x_0)
With: x_0=-1 and y_0=-1
Try by yourself and if it doesn' work look below for the maths:
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Solution:
y'(x)=3x^2
y'(-1)=3=m
Line: y=3x+2