Question

Show that cos2 0 + cos 0 = 1 is not an identity.​

Answer 1

Step-by-step explanation:

2cos^2 theta -1 = 1- cos theta

2cos^2 theta = 2 - cos theta

cos^2 theta = 1- cos theta /2

cos theta = √ 1- cos theta/2

This case is not possible

I'll give u an example

let cos theta = 2 or let cos theta be 1

2 = √ 1-2 / 2 1 = √ 1-1/2

4 = √ -1 2 = 0

4 = i

both the above cases are Not possible therefore,

Cos 2 theta + cos theta = 1

is not an identity

Answer 2

Answer:

same doubt

Step-by-step explanation:

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