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Question
Prove that cos2θ . (1 + tan2θ) = 1. Complete the activity given below.
Activity:
L.H.S = `square`
= `cos^2theta xx square .....[1 + tan^2theta = square]`
= `(cos theta xx square)^2`
= 12
= 1
= R.H.S
Solution
L.H.S. = `cos^2theta*(1 + tan^2theta)`
= `cos^2theta xx sec^2theta` .....`[1 + tan^2theta = sec^2theta]`
= `(cos theta xx sectheta)^2`
= 12
= 1
= R.H.S
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Activity:
L.H.S = `square`
= `square/sintheta + sintheta/costheta`
= `(cos^2theta + sin^2theta)/square`
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= `square`
= R.H.S
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