Sin 17 -sin35 решение

[latex]sin(17)-sin(35) = 2cos( \frac{17+35}{2} )sin( \frac{17-35}{2} ) = 2cos( \frac{52}{2})sin(- \frac{18}{2} )= \\ = 2cos(26)sin(-9) = - 2cos(26)sin(9) [/latex]