Pre Calculus
posted by John on .
Find the Derivative of F(x)=4x2(the previous 2 is squared)2x

y = 4 x^2 2 x
in general derivative of x^n = n x^(n1) so
dy/dx = 4 * 2 x^1  2 x^0
which is
8 x  2 
Now if you have not had that relation you have to do it from the definition
dy/dx = (y at x+h  y at x) /h as h>0
here
y at x+h = 4 (x+h)^2  2 (x+h)
= 4 x^2 + 8 x h +4 h^2  2 x  2 h
y at x = 4 x^2  2 x
difference over h = 8 x + 4 h  2
as h>0 that is
8 x  2
as we already knew