Question

(cos theta - sin theta)^2 -1=

Answer 1

expand \(\bf [cos(\theta)-sin(\theta)]^2-1\) using the binomial theorem, see what you get

Answer 2

multiply out and use the pythagorean identity: \(\sin^2\theta +\cos^2\theta = 1\)

Answer 3

that whole thing is in parentheses ( ) which means sin - cos times sin - cos, or (sin theta - cos theta) squared, and I do not know what binomial theorem is.

Answer 4

foil, (or distribute)

Answer 5

thanks, but that was the wrong answer

Answer 6

what did you get?

Answer 7

http://www.youtube.com/watch?v=1pSD8cYyqUo