Question

5. Prove that: (sin4θ-cos4θ+1)cosec2θ=2

Answer 1

Answer:

Step-by-step explanation:

Solution :

L.H.S. = (sin4θ – cos4θ +1) cosec2θ

= [(sin2θ – cos2θ) (sin2θ + cos2θ) + 1] cosec2θ

= (sin2θ – cos2θ + 1) cosec2θ

[Because sin 2θ + cos2θ =1]

= 2sin2θ cosec2θ [Because 1– cos 2θ = sin2θ ]

= 2 = RHS