2. sint=3/5>0 0<t<П/2 cost>0 sin^2t=9/25 cos^2t=1-sin^2t=1-9/25=16/25 cost=4/5sin(t+П/6)=sintcosп/6+costsinП/6=sqrt(3)/2sint+cost*1/2=3sqrt(3)/10+4/10=(3√3+4)/10cos(П/2+t)=-sint=-3/51. √2cos(П/4-x)-cosx=1/2√2*(√2/2cosx+√2/2sinx)-cosx=1/2cosx+sinx-cosx=1/2sinx=1/2x=(-1)^kП/6+Пk
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2. sint=3/5>0 0<t<П/2 cost>0
sin^2t=9/25 cos^2t=1-sin^2t=1-9/25=16/25 cost=4/5
sin(t+П/6)=sintcosп/6+costsinП/6=sqrt(3)/2sint+cost*1/2=3sqrt(3)/10+4/10=(3√3+4)/10
cos(П/2+t)=-sint=-3/5
1. √2cos(П/4-x)-cosx=1/2
√2*(√2/2cosx+√2/2sinx)-cosx=1/2
cosx+sinx-cosx=1/2
sinx=1/2
x=(-1)^kП/6+Пk