K, so my teacher presented a set of problems and it is basically impossible to get all of them right (it was a competition to see who could do the most). There were a ton of problems and after going to class I still don't understand how to do some of them.
Disprove the following identity by counterexample:
#4
sin^2(x)+cos(x)=0
Everything that I plug in says that this isn't an identity. What am I doing wrong?
Prove the following identities:
#13
cotx-sinx=(cos^2(x)+cosx-1)csc(x)
I spent 2 hours trying to prove this, and I am coming with a nothing.
And the third one
Solve the following:
#14
1-2sin^2(2x)=3sin2x
I have a bunch of these that I didn't get right that I don't understand, but these 3 are really bugging me. I already know the answers, so I mostly care about how to get that answer because so far I haven't been able to figure it out. Any help will be great!!!
Thanks!!! You guys are the bomb-diggity!
I don't know if you guys will be able to help me, but I got halfway through on this problem and I think that I might be doing it wrong.
(16/81)^sin^2(x) + (16/81)^1-sin^2(x) = (26/27)
I know that you can substitute sin^2(x) for 1/4 or 3/4 and the problem will work, but the instructions say "Solve" and I don't think I am solving it very well.