Question

If sinx+siny=3/5 and sinx-siny=2/5 then cot(x+y/2)÷cot(x-y/2)=

Answer 1

sin[x+y]=3/5

sin[x-y]=2/5

remember that cot is the same as 1/tan therefore

first find the value of [x+y] and [x-y]

the inverse of sin of the values given

[x+y]=1.7710

[x-y]=2.5679

1/tan [ [x+y]/2 ]  /  1/tan  [  [x-y]/2  ]=2.771