Math, asked by niharika888, 8 months ago

cos²2+cos²4+cos²6+.......... cos²88

Answers

Answered by sakshisingh27

Step-by-step explanation:

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As you know, sin²x + cos²x = 1 and sin(x) = cos(90-x)

So, sin²46 = cos²(90-46) = cos²(44)

Similarly, sin²48 = cos²42...

Now, we have sin²2 + sin²4 + sin²6 + ... + sin²44 + cos²44 + cos²42 + cos²40 + ... + cos²2 + cos²0.

Pairing sin²2 and cos²2, sin²4 and cos²4, ... , sin²44 and cos²44, we get 1+1+1...+1 and cos²0 = 1

So, ultimately we get 22 ones and cos²90=1 so we get 23 ones.

Therefore the answer = 23.

Answered by deyd46492

Answer:

22 should be the correct answer

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