Question

4 sin’x + 6 cos²x = 5​

Answer 1

4 sin²x + 6 cos²x = 5

4 sin²x + 4 cos²x + 2 cos²x = 5

4(sin²x + cos²x) + 2cos²x = 5

4(1) + 2 cos²x = 5

2 cos²x = 1

cosx = 1/√2

x = π/4 = 45°

Extra information:

sin²x + cos²x = 1

sec²x - tan²x = 1

cosec²x - cot²x = 1