Question

Evaluate: ( sin 31^/ cos 59 ) 2 + ( cos 59^/ sin2 — 4 sin2 45o

Answer 1

Answer:

cos(6721)∘

cos2θ=cos135∘

cos(135)∘=cos(−45+180)=−cos45∘

we know that 

cos2θ=2cos2θ−1

⇒2cos2θ=cos2θ+1

⇒2cos2θ=2−2+1=22−2

⇒cos2θ=42−2

⇒cosθ=42−2

⇒cos6721∘=22−2

Answer 2

Answer:

Hope it helped you mate............ XD

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