Question

Suatu fungsi kuadrat diketahui melalui titik A(-1,0), B(0,2), Dan C(1,3). tentukan fungsi kuadrat tersebut!

Answer 1

F(x) = ax² + bx + c

titik (0,2)
f(0) = a.0 + b.0 +c
 2   = c

titik (-1,0)
f(-1) = a.(-1)² + b.(-1) + c
     0 = a - b + 2
    -2 = a - b............(1)

titik (1,3)
f(1) = a.(1)² + b.(1) + c
    3 = a + b + 2
    1 = a + b...........(2)

elminasi pers (1) dan (2):
-2 = a - b
 1 = a + b ₊
-1 = 2a
  a= -1/2, b= 3/2

f(x) = ax² + bx + c
      = (-1/2).x² + (3/2).x + 2