Prove that: .

formula: – (i)

(ii)

(iii) a² + b² + 2ab = (a + b)²

(iv) a² – b² = (a – b)(a + b)

(v)

multiplying with, we get

using formula (i) and (ii)

using formula(iii) &(iv)

Dividing with

using formula(v)

[we know that tan 45

therefore L.H.S = R.H.S

Hence, Proved.