Question

Pre-Calculus questions
Can someone help solve these equations:
1. cos(x+(pi/4))-cos(x-(pi/4)=1
2. sin x cos x=1/4
3. tan^2 x-3=0

Answer 1

Regarding #(2) sin x cos x=1/4: Try multiplying both sides by 2. The reason for this is that 2sin x cos x has a identity. What is that identity?

Answer 2

I'm not sure

Answer 3

Hint:

sin(2x) = 2sin(x)cos(x)