Find two different ways to show that g(x)= -x^3 +27 has only one x intercept

Which property is illustrated by the statement given below? raj raj.

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

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.