Question

tg=2,4 ; pi<t<3pi/2 найти: cos,sin,ctg.

Answer 1

ctgt=1/tgt=1/2,4=10/24=5/12, tgt=sint/cost=2,4, sint=2,4cost,
sin²t+cos²t=(2,4cost)²+cos²t=cos²t(5,76+1)=6,76cos²t=1, cost=-1/√6,76=-1/2,6=
=-10/26=-5/13, sint=-2,4*(5/13)=-12/13 (минусы стоят,т к  pi<t<3pi/2)