dintre punctele de mai jos cel ce nu aparatine graficiului ​

Răspuns: c)

[tex]a) \: A(1; - 1) \\ f(1) = 4 \times 1 - 5 \\ f(1) = 4 - 5 \\ f(1) = - 1[/tex]

[tex]b) \: A( - 1; - 9) \\ f( - 1) = 4 \times ( - 1) - 5 \\ f( - 1) = - 4 -5 \\ f( - 1) = - 9[/tex]

[tex]c) \: D( - \frac{1}{3} ; \frac{2}{3} ) \\ f( - \frac{1}{3} ) = 4 \times ( - \frac{1}{3} ) - 5 \\ f( - \frac{1}{3} ) = - \frac{4}{3} - 5 \\ f( - \frac{1}{3} ) = - \frac{4}{3} - \frac{15}{3} \\ f( - \frac{1}{3} ) = - \frac{19}{3} ≠ \frac{2}{3} ⇒D( - \frac{1}{3} ; \frac{2}{3} ∉ \: Gf

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Răspuns:

un punct A(x,y) aparține lui Gf dacă

f(x)=y

f(1)=-4-5=-1 ,adevarat

punctul aparține

f(-1)=9

f(-1)-4-5=-9,adevarat,apartine

f(-1/3)=2/3

f(-1/3)=-4/3-5=-(4-3*5)/3=-11/3,fals

nu aparține

f(1/3)=-11/3

4/3-5=(4-5*3)/3=(4-15)/3=-11/3,adevarat ,apartine