Question

If cos θ = c, then sin²θ/2 equals

1) 1-c/2
2) 1+c/2
3) 1-c/c+c
4) 1-c/4

Answer 1

cos^2 = c I suspect typo
1 - sin^2 = c
sin^2 = 1 - c

sin^2 /2 = (1-c)/2 not 1 - c/2

I am not a mind reader. Please check what you type to make sure it makes sense.

Answer 2

I typed what i wrote correctly these questions are from a work sheet therefore your smart comments aren't needed if you simply can not solve it, just don't post.