Question

Prove that sin(20°)cos(40°)+cos(20°)sin(40°)=√3/2 ?

Answer 1

`"see explanation"`

Explanation:

`"using the "color(blue)"addition formula for sine"`

`•color(white)(x)sin(x+-y)=sinxcosy+-cosxsiny`

`"thus the expression on the left side represents"`

`sin(20+40)^@=sin60^@=sqrt3/2`