Question

Se considera functia f:R -> R ; f (x) = x-3
a) calculati f(2)+ f(4)
b) realizati graficul functiei f intr un sistem de axe ortogonale.

Answer 1

F(2)=2-3=-1
F(4)=4-3=1
F(2)+F(4)=0
x=0 -----> F(0)=0-3=-3 ------> A(0;-3)
F(x)=0 ------> 0=x-3----> x=3 --------> B(3;0)

Answer 2

 b) pt. x =0 , f(x) =-3, y=-3, A(0;-3)
pt.y=0 ⇒ 0=x-3⇒, x=3 ,⇒ B(3;0)

a) f(2) +f(4)=-1+1=0