Question

f(x): R ->R
f(x)= ax+b
A(-1;1) €Gf
B(1;5) €Gf

Sa se determine funcția

Answer 1

Răspuns:

Explicație pas cu pas:

-a+b=-1

a+b=5         2b=6       b=3   si a=2

f(x)=2x+3

Answer 2

f(x):R→R;

f(x)=ax+b;  

A(-1, 1)∈Gf  ⇒f(-1)=1;

-a+b=1;

B(1, 5)∈Gf ⇒f(1)=5;

a+b=5;

$\left \{ {{-a+b=1;} \atop {a+b=5;}} \right. =>\left \{ {{-a+b=1;} \atop {a=5-b;}} \right. =>\left \{ {{-5+b+b-1=0;} \atop {a=5-b;}} \right. =>\left \{ {{b=3;} \atop {a=5-3=2;}} \right. \\\\=>f(x)=2x+3;$