Question

Cum pot rezolva acest exercitiu?

Answer 1

g | f ⇒ f(x)= g(x)*Q(x), unde Q este un cat oarecare
g(1)=0 ⇒ f(1)= g(1)*Q(1)=0
f(1)= a+b -3=0⇔a=3-b (1)
1 rad dubla pt g ⇒ f'(1)=0
f'(x)=4aX³+3bX²
f'(1)=0⇔4a+3b=0 (2)
Inlocuim a de la (1) in rel. (2) ⇒ 4(3-b)+3b=0⇔12-4b+3b=0⇔b=12
⇒ a= -9
x1²+x2²+x3²= (x1+x2+x3)² - 2*(x1x2+x1x3+x2x3)= S1² -2*S2= (-b/a)²-2*(c/a)
$(- \frac{12}{-9})^2 -2* \frac{0}{-9}= (\frac{4}{3})^2= \frac{16}{9}$