Question

Aflati zerourile functiei F : R R ,
$f(x)= x^{2} -8x+12$

Answer 1

f(x)=0
x^2-8x+12=0
Coeficientii sunt a=1,b=(-8),c=12,
Δ=b^2-4ac=(-8)^2-4*1*12=64-4*12=64-48=16>0,
iar √Δ=4.
Deci ecuatia are solutiile reale x1,2=[(-b)±√Δ]/(2a)=[-(-8)±4]/(2*1)=(8±4)/2.
x1=(8-4)/2=4/2=2
x2=(8+4)/2=12/2=6
Multimea de solutii este S={2,6}.