Question

63. Folosind regulile de calcul cu derivate, să se calculeze derivata de ordinul
doi pentru f:D → R:
a) f(x) = 2x ^2 + 5x;
b) f(x) = x^3– 4x;
c) f(x) = e^x+x;
d) f (x) = x + In x;
e) f(x) = x Inx;
f(x)= x^2 e^x
​

Answer 1

a)f(x)=2x+1

2x+1=0

2x=-1

x=-1/2

f(0)=2·0+1=1

f(-1/2)=0

b)f(x)=3-5x

3-5x=0

-5x=-3   inmultim -1

x=3/5

x=0,6

f(0)=3

f(0,6)=0

c) f(x)=√10x

√10x=0

x=0

f(0)=0

d)f(x)=x/2-7,2

x/2-7,2=0

x/2=7,2

x/2=72/10

10x=72·2

x=72·2/10

x=72/5

x=14,4

f(0)=-7,2

f(14,4)=0