If (1+4x²) cos A = 4x, then let us show that,

6

If then let us show that,

6

If then let us show that,

7

If x = a sin θ and y = b tan θ, then let us prove that,

8

If sin θ + sin² θ = 1, then let us prove that, cos² θ + cos⁴ θ = 1.