Question

If cot A/2=√1+a/1-a cot theta/2 then cos theta=
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Answer 1

Answer:

I don't know the answer

pls keep properly

Answer 2

Answer:cosA-a/1-acosA

Step-by-step explanation:

We have, cotA/2=√1+a/1-a cot(theta/2)

cot^2 A/2=(1+a/1-a)cot^2(theta/2)

(cos^2 A/2 / sin^2 A/2)(1-a/1+a) =cos^2(theta/2) / sin^2(theta/2)

(1+cosA)(1-a) / (1-cosA)(1+a)=1+cos(theta)/1-cos(theta)

1-a-acosA+cosA / 1+a-acosA-cosA =1+cos(theta / 1-cos(theta)

Apply componendo and dividendo method,

2(1-acosA)/2(cosA-a)=2/2cos(theta)

cos(theta)=cosA-a/1-acosA