Question

Solve the following:
1. Given that: sinA = a/b, then cosA =?
2. If sin A + sinA = 1, then cos? A + cos4 A =?
3. If sin A = 1/2 and cos B = 1/2, then A+B =?

​

Answer 1

Answer:

1)√a+b/b

2)cos =sin,A+4cosA= 4cos2A

3)a+b=90