Solve 28 less than or equal to 4n​

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.

What is the best approximation for the area of a circle with a radius of 4 m ? use 3.14 to approximate pi

Answer for 15 points (look at the image)