The selling price of 20 articles is equal to the cost price of 22 articles. The gain percentage is

The value of 1/(1+tan²θ) + 1/(1+cot² θ) is

If tan θ = 3/4 and  θ is acute, then cosec  θ is equal to

If cos⁴ θ - sin4 θ = 2/3, then the value of 1-2 sin² θ is

If tan ∝ = n tan β and sin ∝ Q = m sin β, then cos² ∝ is

If cos θ + sin θ = √2 cos θ, then cos θ - sin θ is