is equal to

θθ then the value of θθ?

If 0 ≤ θ ≤ 90⁰ and 4cos²θ - θ + 3 = 0, then the value of θ is : 

If cos θ = , then tan θ is equal to.

If cos²α + cos²β = 2, then the value of tan³ α + sin⁵ β is :

If θθθθ= sinθ then the value of sin θ is :

What is the value of

If θ then find cos²θ :