Trigonometri Soruları

S-1)bir ABC üçgeninde,tan a=1/3, tanb=1/2 ise tanc kaçtır?(-1) s-2)x,y∈(0,pi/2) ise, sinx=4/5, cosy=5/13 ise cos(x+y)=?? (-33/65) ...

:confused:s-1)x=pi/26 ise, (sin4x.cos3x+cos4x.sin3x) / (cos7x.cosx+sin7x.sinx) =? (1) s-2)sin(x-pi/4) / sin(x+pi/4)=1/2 ise cot x=? (1/3) ...