Question

(3cos a - 5sin a)/(2cos a - sin a) при tg=1

Answer 1

 

$если tga=1=> a=pi/4 или a=3pi/4 (3cospi/4-5sinpi/4)/(2cospi/4-sinpi/4)=(3*/sqrt2/2-/sqrt2/2)/2*sqrt2/2-/sqrtx/2=-2*/sqrt2/2//sqrt2=-1$