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1+ sin2a/cos2a


(1 + sin2 \alpha )/(cos2 \alpha )


1 Answer

5 votes

Answer:


(1 + sin(2 a))/(cos(2 a) ) = (cos(a)+ sin(a))/(cos(a) - sin(a) )

Explanation:

The question is incomplete; however, I'll simplify the given expression as far as it can be simplified.

Given


(1 + sin(2 a))/(cos(2 a) )

Required

Simplify


(1 + sin(2 a))/(cos(2 a) )

In trigonometry:


sin(2a) = 2sin(a)cos(a)

So, the expression becomes:


(1 + 2sin(a)(cos(a))/(cos(2 a) )

Also in trigonometry:


cos^2(a) + sin^2(a) = 1

So, the expression becomes:


(cos^2(a) + sin^2(a) + 2sin(a)(cos(a))/(cos(2 a) )

Also:


cos(2a) = cos^2(a) - sin^2(a)

So, we have:


(cos^2(a) + sin^2(a) + 2sin(a)(cos(a))/(cos^2(a) - sin^2(a) )

Rearrange the numerator:


(cos^2(a) + 2sin(a)cos(a) + sin^2(a))/(cos^2(a) - sin^2(a) )

Expand the numerator


(cos^2(a) + sin(a)cos(a)+ sin(a)cos(a) + sin^2(a))/(cos^2(a) - sin^2(a) )

Factorize:


(cos(a)(cos(a) + sin(a))+sin(a)(cos(a)+ sin(a)))/(cos^2(a) - sin^2(a) )


((cos(a) + sin(a))(cos(a)+ sin(a)))/(cos^2(a) - sin^2(a) )

Apply difference of two squares to the denominator


((cos(a) + sin(a))(cos(a)+ sin(a)))/((cos(a) - sin(a))(cos(a) + sin(a)) )

Divide the numerator and denominator by
cos(a) + sin(a)


(cos(a)+ sin(a))/(cos(a) - sin(a) )

Hence:


(1 + sin(2 a))/(cos(2 a) ) = (cos(a)+ sin(a))/(cos(a) - sin(a) )

User Hendrik Beenker
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