Trigonometric Equations

Question

Using inverse trigonometric functions, find a solution to the equation  cos(x)=.7 in the interval 0 to 4pi. Then, use a graph to find all other solutions to this equation in this interval. Enter your answers as a comma separated list.

I have the first two answers, .7954, and 5.4878. However, I still need to find two answers but I am not sure how to.

Thank you!!

Answer 1

Since the interval is from 0 to 4π, add 2π to both numbers.