1)1/49 в степени -x/2=7 2) tga+tgb/tga-tgb

1) 





2) (tga + tgb)/ (tga - tgb) ; Пусть (tga + tgb) = A  и (tga - tgb) = B

A = sina/cosa + sinb/cosb = [sina*cosb + sinb*cosa]/ cosa*cosb =
= sin(a+b)/cosa*cosb

B = sina/cosa - sinb/cosb = [sina*cosb - sina*cosa]/cosa*cosb* = 
=sin(a-b)/cosa*cosb

A/B = sin(a+b)/cosa*cosb : sin(a-b)/cosa*cosb = sin(a+b)/sin(a-b)