How do you find the equation of the line tangent to the curve #y=x^3# 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#