X³-10x<0
x(x²-10)<0
x(x-√10)(x+√10)<0
- + - +
_____________-√10___________0___________√10____________
x∈(-∞;-√10)∨(0;√10)
X^2+xy+11x+11y=x^2+11x+xy+11y=x(x+11)+y(x+11)=(x+y)(x+11)
2/3v7 = 2v7/28
4/(v11 +3) = 4(v11 - 3)/2= 2(v11 - 3)=2v11-6
1) -4а(3а²-5а-2)=-12а³+20а²+8а
Y=4sinx+10cosx-4xcosx-7
y`=4cosx-10sinx-4cosx+4xsinx=sinx(4x-10(=0
sinx=0⇒x=0∉(π/2;π)
4x-10=0⇒x=2,5∉(π/2;π)
y(2,5)=4sin2,5-7=4*1/2-7\2-7=-5
(2.5;-5)-точка минимума