Răspuns:
103
a.f(x)=5x+4x²
f `(x)=5+4x
5+4x<0
5<-4x
x> - 5/4 x∈(-5/4,+∞)
c)f(x)=x²-4x
f `(x)=2x-4
2x-4<0
2x<4
x<4/2
x<2
x∈(2,+∞)
d.f(x)=4x-x³/3
f `(x)=4x-3x²/3=4x-x²
f `(x)<0 4x-x²<0
rezolvi ecuatia
4x-x²=0
x(4-x)=0
x1=0 x2=4
Conf regulii semnuli pt functia de grd 2
x∈(-∞,0)U(4,∞)
4)
104.
f(x)=x²+x+1
ecuatia tangentei
y-f(xo)=f `(xo)(x-xo)
xo=1
f(1)=1²+1+1=1=1+1=3
f`(x)=2x+1
f `(1)=2*1+1=2+1=3
y-3=3(x-1)
y=3x-3+3
y=3x
Explicație pas cu pas:
