How do you calculate #(d^2y)/(dx^2)# of #y=-4x^2+7x#?

1 Answer
Nov 2, 2016

# (d^2y)/(dx^2)=-8 #

Explanation:

You differentiate twice to get the second derivative

So, # y=-4x^2+7x #

We differentiate wrt #x# to get the "First Derivative":
# dy/dx=(-4)(2)x^1+7 #
# :. dy/dx = -8x+7 #

And we differentiate the First Derivative wrt #x# to get the "Second Derivative":
# dx = -8x+7 #
# :. (d^2y)/(dx^2)=-8 #