Question

please answer thus question ​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

If sintheta=a/b

Then,

sin²theta+cos²theta=1

(a/b) 2+cos²theta=1

a²/b²+cos²theta=1

cos²theta=1-a²/b²

costheta=under root 1-a²/b²

costheta=1-a/b

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