Question

Prove that Sin2theta +cos2theta =1​

Answer 1

Solution :-D

Let a, b, c be lengths of right

angled triangle

By definition

Sin 0 = b/c (hypotenuseopposite side)

Cos 0 = a/c (hypotenuseadjacent side)

Sin2 0 + cos2 0 = c2 b2 + c2 a2 = c2 a2 + b2

From Pythagoras theorem

C2 = a2 + b2

... C2 a2 + b2 = 1

Sin2 0 + cos2 0 = 1

Hence, proved.

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Hope it's help you :-D