1
-8/13;-7/13;-5/13;-1/13;0;1/10
2
1,09;1,009;1;0;-1,2;-1,24
3
x/y=0 x=0 y=5;x=0 y=-100
x/y>0 x=6 y=2;x=-10 y=-5
x/y≤0 x=0 y=200;x=4 y=-2
x/y=1 x=5 y=5;x=-17 y=-17
x/y≥0 x=0 y=6;x=-10 y=-2
x/y=-1 x=-24 y=24;x=99 y=-99
x/y<-1 x=-14 y=2;x=16 y=-4
4
a>0,b>0⇒ab>0верно
a=5 b=7 5*7=35>0
ab>0⇒a>0,b>0 не верно
a=-5 b=-7 a<0 U b<0 ab>35
Sin²x+cos²x=1⇒ sin x=√(1-cos²x)=√(1-0,36)=0,8. Ответ: 0,8.
Cos(a) = sqrt(1-(sin(a)^2) = 2*sqrt(6)/5
tg(a) = sin(a)/cos(a) = 1/(2*sqrt(6))
tg(a) = AC/BC
AC = BC*tg(a) = 1/(2*sqrt(6))*6*sqrt(6) = 3
<em>f(x) = 2x - 5</em>
а) f(0) = 2·0 - 5 = -5
f(-1,5) = 2·(-1,5) - 5 = -3 - 5 = -8
б) f(x) = 18
2x - 5 = 18; 2x = 23; x = 11,5
f(x) = 0
2x - 5 = 0; 2x = 5; x = 2,5