Y=4x-x²
y=x(4-x),тогда x=0 или 4-x=0
x=0. x=4
x²-2x-224
D= 4+896=900
x1= (2+30)/2= 16
x2= (2-30)/2= -14
(x-16)*(x+14)
или
x²-2x-224= x²-16x+14x-224= x(x-16)+14(x-16)= (x+14)*(x-16)
1) f(x)=√(6x+7) x₀=3
f`(x)=6/(2/√(6x+7)
f(3)=6/(2*(√6*3+7))=6/(2*√25)=6/10=0,6.
2) f(x)=cos⁴x x₀=π/4
f`(x)=-4*cos³x*sinx
f`(π/4)=-4*cos²(π/4)*sin(π/4)=-4*(√2/2)³*(√2/2)=-4*(√2/2)⁴=-4*1/4=-1.
Домножим обе части на 18:
6*x(x-2)-9*5x+2=0
6x^2-12x-45x+2=0
6x^2-57x+2=0
a=6
b=-57
c=2