Question

3. Stabiliți dacă punctele A(12; 2), B(-8; -2), 3
3
C(2; 0) sînt coliniare.

Answer 1

A(12,2) € Gf => f(12)=2
f(12)=2 => 2 = 12a + b
B (-8,-2) € Gf => f(-8) = -2
f(-8) = -2 => -2= -8a + b
{12a+ b = 2 | • (-1)
{b - 8a = -2
{-12a - b = -2
{ -8a + b = -2
__________
-20a = -4
-a = -1 / 5
a = 1/5
12a + b = 2 => b= 2 - 12/5
b = 10/5 - 12/5
b = -2/5
Daca C (2,0) € Gf => f(2) = 0
f(2) = 0 => 0 = 2/5 - 2/5
0 = 0 => C € Gf => Adevarat