Proof: L.H.S: ∵ sin(90°-θ)=cosθ ⇒ sin2 (90°-θ) =cos2θ = = [∵ cot(90°-θ) = tan θ] = = [∵ cos2 θ + sin2 θ = 1] = [∵ ] = 1 : R.H.S

Q15 of 58 Page 8

Show that =1

Proof:

L.H.S:

∵ sin(90°-θ)=cosθ

⇒ sin² (90°-θ) =cos²θ

= [∵ cot(90°-θ) = tan θ]

= [∵ cos² θ + sin² θ = 1]

= [∵ ]

= 1

: R.H.S

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