Question

How do you simplify `sin(x+y)` to trigonometric functions of x and y?

Answer 1

sinxcosy +cosxsiny

Explanation:

using `color(blue)" Addition formulae "`

`• sin( a ± b ) = sinacosb ± cosasinb`

`• cos (a ± b ) = cosacosb ∓ sinasinb : color(red)" note sign change "`

`• tan( a ± b ) = (tana ± tanb)/(1 ∓ tanatanb)`

[ >`( tan a ± b ) " can be derived from using "( sin( a ± b))/(cos(a ± b )`]