Hi! Please help I am very desperate and I need it solved. Thanks!

Which representation has a constant of variation of -2.5

Which graph represents the parent function of y=(x+2)(x-2)

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.