Question

If a is a acute angle cos A =12/13 then find (1+cos A) (1-cos A) / (1+sin A) (1- sin a)

Answer 1

sin^2A = 1 - cos^2 = 25/169
cos^2= 144/169

(1+ cos A)(1-cosA)/(1+sinA)(1-sinA)
1 - cos^2/1- sin^2
sin^2/cos^2
25/169/144/169
25/144

hope it helps uh!!