Write $2.161616 as a fraction and mixed number

Does the point (1, sqrt 7) lie on circle shown.

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.

Hi, can anyone show me how to do this problem? 100 points for this. in advance