SOLUTION:
a.

This is FALSE ; the correct formula is ;

b. The equation

has multiple solutions, this is FALSE. It has no solution. The maximum value of cosine is 1, It can't go above 1.
c. The equation

has exactly one solution, this is also FALSE, the equation has an infinite number of solutions.
d. The function

has a period of 12, this is FALSE, the period is given as;

Thus, the period is 24.
e. Of the six basic trigonometric functions, only tangent and cotangent have a range of

This is TRUE