Question

Differentiate -e^-x sinx + e^-x cosx

Answer 1

Dy/dx = e^x cosx + e^-x cosx
Is this right?

Answer 2

Nope. The computer does not agree.

Answer 3

2(e^-x cosx)

Answer 4

You missed the negative sign.

Answer 5

Whats the correct answer?

Answer 6

\(-2e^{-x}\cos(x)\)

Answer 7

thom is right. you need to use the product rule on each bit.

Answer 8

might be easier if you re-write as

e^-x (cosx - sinx)

but still should be doable both ways

Answer 9

What is the working again?

Answer 10

Differentiation of cosx is - sin x, no?

Answer 11

yes

Answer 12

whats the working? I can't seem to be getting the negative.