Question

упростите sinx+siny/cosx+cosy

Answer 1

$\frac{sinx+siny}{cosx+cosy} = \frac{2sin \frac{ x+y }{2}cos \frac{ x-y}{2} }{2cos \frac{x+y}{2}cos \frac{x-y}{2} } = \frac{sin \frac{x+y}{2} }{cos \frac{x+y}{2} } =tg \frac{x+y}{2}$