Question

Determinați coordonatele pct. de intersecție ale reprezentării grafice a fcț. f:R->R cu axele de coordonate:
a)f(x)=-2x-2
b)f(x)=6x+2

Answer 1

b)

$\it{Gf\cap Ox =M(x, 0)}$
 

[tex]\it{M(x, 0) \in Gf \Leftrightarrow f(x)=0\Leftrightarrow 6x+2=0\Leftrightarrow 6x=-2 \Leftrightarrow x=-\dfrac{2}{6} \\\;\\ \Leftrightarrow x= -\dfrac{1}{3}}[/tex]


 $\it{Deci, \ \ \ Gf \cap Ox =M\left(-\dfrac{1}{3}, 0\right).}$ 

[tex]Gf \cap Oy = P(0, y) \\\;\\ P(0, y) \in Gf \Longrightarrow f(0)= y \Longrightarrow \ 2=y \Longrightarrow y=2\\\;\\ Deci, \\\;\\ Gf \cap Oy = P(0, 2) .[/tex]