1. Double Angles, half angles, radian solutions and more

I got my math study guide today and everything looks like arabic

I need help on pretty much all of it, but this is what I'm asking about for now:

1.) Find all the radian solutions for the following equation: 4sin^2 x - 1=0

2.) Simplify the following expression by using a double-angle formula or a half-angle formula: 1-2sin^2 (x/12)

3.) Find the quotient z1/z2 in trigonometric form, if z1=cos(pie) +i sin(pie)and z2=5cos(pie/2) + 5i sin(pie/2)

2. 1.) Find all the radian solutions for the following equation: 4sin^2 x - 1=0
this one will factor ... $(2\sin{x} - 1)(2\sin{x} + 1) = 0$

use the zero product property and solve for x.

2.) Simplify the following expression by using a double-angle formula or a half-angle formula: 1-2sin^2 (x/12)
hint ... $\cos(2u) = 1 - 2\sin^2(u)$

3.) Find the quotient z1/z2 in trigonometric form, if z1=cos(pi) +i sin(pi)and z2=5cos(pi/2) + 5i sin(pi/2)
if $z_1 = r_1[\cos(\theta_1) + i\sin(\theta_1)]$ and $z_2 = r_2[\cos(\theta_2) + i\sin(\theta_2)]$ , then ...

$\frac{z_1}{z_2} = \frac{r_1}{r_2}[\cos(\theta_1-\theta_2) + i\sin(\theta_1-\theta_2)]$