Thread: need help with homework

if sin 70=t write the following in terms of t:

1] cos 160
2] cos 70
3] sin 140

you need to use the expansion method right?

For #1, use the identity .

For #2, use the Pythagorean identity .

For #3, use the double-angle identity .

In all three cases, substitute 70° for x.


01

could you give me an example for one of them?

01

wow i don't know why i confused myself with this stuff. Thanks alot i understand now

EDIT: I am sleep deprived. Sigh.