Question

What is the value of cos2A/(1 + sin
A)?

Answer 1

Answer:

the answer is 135

Answer 2

Step-by-step explanation:

(1 - cos2A)/sin2A = tanA

Use the double-angle formulas:

sin2A = 2sinA cosA

cos2A = cos²A - sin²A = 2cos²A - 1 = 1 - 2sin²A

along with the definition:

tanA = sinA / cosA

EDIT:

Bear in mind that this identity works everywhere except where sin2A = 0; which is:

A = ½nπ

where n = any integer, +, -, or 0.

Note that this also covers values where cosA = 0.