Question

Why is the derivative of (1-x)^3 negative? I can see 3(1-x)^2, but why -3(1-x)^2?

Answer 1

That's what the chain rule tells us. In other words, that is because the derivative of (1-x) is -1.

Answer 2

Thanks, AnwarA.

Answer 3

You're welcome!

Answer 4

(U^n ) = n U^(n-1) * U'
U = 1 -x -> U' = -1
=> derivative result is negative!