Question

find the first derivative of y=1-cos2x + 2cos^2x.

Answer 1

you have to use chain rule with the cos:
\[\cos(ax) dx= asin(ax) \]

Answer 2

ok, thank you!

Answer 3

np

Answer 4

just a note:
d/dx cos(x) = -sin(x)
so above there should be a neg sign in front of asin(ax)

Answer 5

ops, confused with integrals hehe. Thanks cow

Answer 6

\[y=1 - \text{Cos}[2*x] + 2*\text{Cos}[x]^2 = 2 \]
Derivative of 2 is zero.