f(x) = - 4x²
f(x) = 0 ; - 4x² = 0 ; x = 0
f : R → R f'(x) = - 8x radacina derivatei este x =0
x - ∞ 0 + ∞
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f'(x) + + 0 ----- ----
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f(x) -- -- 0 -- --- ---
varful x varf = 0 ⇒ V ( 0 ; 0) este punct de extrem , punct de maxim
axa de simetrie x = 0
semnul ∀ x∈ R , f(x) ≤ 0
daca x∈( -∞ , 0 ) functia este monoton crescatoare
daca x∈ [0, +∞ ) functia este monoton descrescatoare
f(x) = 2,3x² f'(x) = 4,6x
f(x) =0 f'(x) = 0
2,3x²=0 4,6x =0
x=0 x = 0
x - ∞ 0 + ∞
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f ' -- -- 0 + + +
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f monoton descr. V ( 0 ; 0) monoton crescat
punct de minim
axa de simetrie x=0
