Question

Math Analysis:
Use fundamental identities to simplify the expression.
14. sin^2 x + sinx - 1 + cos^2 x
15. cotx sinx - tanxcosx

Answer 1

\[sin^2x + cos^2x = 1\]
use this identity in the first one.

\[cotx = \frac {cosx}{sinx}~~and ~~tanx=\frac {sinx}{cosx}\]

use this in the second one.

Answer 2

14. sin^2 x + cos^2 x = 1, so 1 - 1 + sin x = sin x
15. cot x = (cos x)/(sin x), so cotx sinx = cos x. tan x = (sin x)/(cos x), so tanx cosx= sin x.
So the end result is cos x - sin x

Answer 3

#15. so far i got
cos x - sin x
what do i do next?

Answer 4

that's it. you let it remain that way for #15. That's as simplified as it can get.