Question

using definition,find the derivatives of the following functions at the indicated points : f(x) =1-4x² at x=1​

Answer 1

f(x) = 1-4x²

d[f(x)]/dx = 0-2(4x)^2-1

d[f(x)]/dx = -8x

at x=1

d[f(x)]/dx = -8(1) = -8