Question

If ΔABC is a right angled at c,Then the value of cos(A+B)=

Answer 1

let angle is equals to 30 then Angle B will equally be 30 then Cos 60 is 1 upon 2 and cos 30 is under root 3 upon 2 and Cos A + cos B we get 1 + under root 3 / 2