Question

Given that
$\cos^{2} theta \: - sin^{2} theta \: = \: \frac{3}{4}$
What is the value of cos theta?​

Answer 1

Answer:

cos θ= √7/2√2

Step-by-step explanation:

cos² θ - sin² θ = cos2 θ = 2cos² θ - 1 [ CLASS 11 formula]

So,

2cos² θ - 1 = 3/4

2 cos² θ = 7/4

cos² θ = 7/8

cos θ = √7/√8

cos θ = √7/2√2