Expressed in a + bi form, (2+3i)^2 is equivalent to ?

Negative 5 1/12 + negative 4 1/4 + 6 3/4

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.

Consider that lines b and c are parallel. what is the value of x? what is the measure of the smaller angle?