Question

(1-cos B)(1+cos B)/(1-sin B)(1+sin B ) =1/3
Where b is 30

Answer 1

Here is your answer :-

I m taking B is b for my comfort ..

(1-cosb)(1+cosb) / (1-sinb)(1+sinb)

1-cos²b / 1- sin²b

1-cos²30° / 1-sin²30°

1- √3/2 / 1-1/2

2-√3/2 / 2-1/2

2-√3 /1