Find the equation of the normal line to the curve at x= -2 if f(x)= x^3

Question

mertsj · Answer

1.  The normal is the perpendicular. 
2.   Find the first derivative.  
3.  Replace x in the first derivative with -2.
4.  That is the slope of the tangent.
5.  Take the reciprocal of the answer to # 4 and change it to its opposite.
6.  That is the slope of the normal.
7.  (-2,-8) is a point on y = x^3
8.  Find the equation of a line whose slope is the answer to #5 and contains the point (-2,-8)

anonymous · Answer

How do I "Find the first derivative"

mertsj · Answer

You learn that in calculus.  Have you had calculus or pre-calc?

anonymous · Answer

im in calculus right now

mertsj · Answer

At the end of the first semester, right?

anonymous · Answer

yes

mertsj · Answer

y'=3x^2

anonymous · Answer

oh okay i understand the power becomes the constant and the power is subtracted by one. thank you!!

mertsj · Answer

yw