Question

cos2a = 1-2sin^2(a) for all values of a

A. True
B. False

Answer 1

Once again with my improper math techniques I believe it is True because cos2a does equal 1-2sin^2a

Answer 2

LOLLLLLL.
Are you just using guess and check?

Answer 3

Yep

Answer 4

Cos2x = 1 - 2sin^2x is a trig identity that you need to know.

Answer 5

Ah ok. I will find a list and study! Thank you for telling me that

Answer 6

no problem :)

Answer 7

I know one day the improper math techniques are going to bite me in the butt

Answer 8

xD probably...

Answer 9

So I am assuming this question is true.

Answer 10

yes it is truee..
Cos 2x has three different things it could equal to :)
http://prntscr.com/7j2qax

Answer 11

Great! Thank you for the help!

Answer 12

no problemoooo~