-10м(2м+4р)
-20м^2-40мр
-20м(м+2р)
1) 5x^2+2x-3
D=4+60=64
x=(-2+8)/10=6/10=3/5
x=(-2-8)/10=-1
5*(x-3/5)(x+1)=(5x-3)(x+1)
2) 3x^2+4x-7
D=16+ 84=100
х=(-4+10)/6=1
х=(-4-10)/6=-14/6=-7/3
3*(х+ 7/3)(х-1)=(3х+7)(х-1)
3) -3x^2+5x-8
D=25+96=121
x=(-5+11)/(-6)= -1
x=(-5-11)/(-6)= -16/(-6) =8/3
-3*(x- 8/3)(x+1)=(-3x+8)(x+1)
tg(pi/12)=<span>√</span>(1-cos(2pi/12))/<span>√</span>(1+cos(2pi/12))=<span>√</span>(1-cos(pi/6))/<span>√</span>(1+cos(pi/6))=<span>√</span>(1-<span>√</span>3/2)/(1+<span>√</span>3/2)=<span>√</span>(2-<span>√</span>3)/<span>√</span>(2+<span>√</span>3)=<span>√</span>(2-<span>√</span>3)^2/((2+<span>√</span>3)(2-<span>√</span>3))
2²ˣ + 2ˣ⁺² - 5 > 0
2ˣ = t
t² +4t -5 > 0 Корни -5 и 1
-∞ -5 1 +∞
+ - + это знаки t² +4t -5
IIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIII
a) t > -5 б) t < 1
2ˣ > -5 2ˣ < 1
x - любое x < 0