12•2=24(весь путь)
24:4=6(должна лететь муха)
4sin^2(x)+ 9tg^2(x) = 4
9tg^2(x) = 4-4sin^2(x)
9tg^2(x) = 4(1-sin^2(x))
9(tgx)^2=4(cosx)^2
9(1-cos2x)/(1+cos2x)=2+2cos2x
9(1-cos2x)=2(1+cos2x)^2
cos2x=t
9(1-t)=2(1+t)^2
2+4t+2t^2-9+9t=0
2t^2+13t-7=0
D=169+56=225
1.t=(-13+15)/4=1/2cos2x=1/2 ; 2x=-+p/3+2pk
x=-+p/6+pk
2. t=(-13-15)/4=-7 -->cos2x=-7
x=-+p/6+pk
7, 045*100=704, 5!!!!!!!
0, 8*1000=800!!!!
25, 14:10=2, 514!!!!
6, 38:100=0, 0638