Prove the following identity :
sin α . cos α .
tan α = (1 – cos
α) (1 + cos
α)

(98 points) i need with 5 questions. answer definitions are welcomed, but not necessary.

If two angles of a triangle have equal measures and the third angle measures 90°, what are the angle measures of the triangle? a. 60°, 60°, 60° b. 45°, 90°, 90° c. 30°, 30°, 90° d. 45°, 45°, 90°

Hormones perform important functions within the reproductive system. during puberty, a number of changes occur in the body. which hormone is responsible for the development of these characteristics in the female? estrogen progestin progesterone testosterone