1. Solve cos x(cos x - 1) = 0.
Ans: pi/2 + n pi, and 2 n pi
2. 2 cos x - 1 = 0
Ans: x = pi/3 + 2 n pi, and x = 5pi/3 + 2 n pi
3. Solve 4 sin^2 x - 3 = 0
Ans: x = pi/3 + n pi, and 2pi/3 + n pi
4. What is one solution to (sqrt2) sinx + 1 = 0?
Ans: x = pi/6
1,2,3 look good.
#4 sinx = -1/√2
bzzzt.