Cos²t×tg²t-sin²t×cos²t=cos²t×sin²t/cos²t-sin²t×cos²t=sin²t-sin²t×cos²t=
sin²t(1-cos²t)-sin²t×sin²t=sin⁴t
20х²-5х+24х-6=0
20х²+19х-6=0
а=20.b=19,c=-6
D=19²-4*20*(-6)=361+480=841
-19+29
x1= _______= 0.25
40
-19-29
x2= _________ = -1.2
40
Ответ:0,25;-1,2