PLEASE EXPLAIN WHAT THESE MEAN- WORTH 30 POINTS AND ILL GIVE BRAINLIEST

Which of the following best describes the graph below? a. it is a function, but it is not one-to-one. b. it is a one-to-one function. c. it is not a function. d. it is a many-to-one function.

Which of the following is the shape of a cross section of the figure shown below

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).