Write an equivalent expression for 4(2x+5)

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

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 absolute value of the complex number -4-sqrt2i