X^3<span>+4x^2-7x-10=0
x(x^2+4x-7)-10=0
x-10=0 x^2+4x-7=0
x=10 D=k-ac=2^2-1*(-7)=4+7=11
x1=-2+</span>√11
x2=-2-√11
1)9x-3>10x-14
9x-10x>3-14
-x>-11
x<11
2)5x+20<8x-10
5x-8x<-20-10
-3x<-30
x>10
дальше по аналогии
По теореме виета с=5х1*5х2=25x1*x2=-25*1=-25
b=-(x1+x2)=-5*7=-35
y=x²-35x-25
<span>=2cos2a*cosa/(2sina*cosa)+2sin2a*cosa/(1+2cos²a-1)=cos2a/sina+sin2a/cosa=(1-2sin²a)/sina+2sina*cosa/cosa=1/sina-2sina+2sina=1/sina=Coseca</span>