Diketahui fungsi f(x) = ax2 + bx + c, jika bayangan f(-1) = 7, f(0) = 4, dan f(1) = 3, maka fungsi f dapat dirumuskan menjadi?

f(x) = ax² + bx + c

f(-1) = a(-1²) + b(-1) + c
7 = a - b + c

f(0) = a(0²) + b(0) + c
4 = c

f(1) = a(1²) + b(1) + c
3 = a + b + c

a - b + c = 7
a + b + c = 3
------------------ (ditambah)
2a + 2c = 10 >>>>>>> c = 4
2a + 2(4) = 10
2a + 8 = 10
2a = 10 - 8
2a = 2
a = 2/2 = 1

a + b + c = 3
b = 3 - (a + c)
= 3 - (1 + 4)
= 3 - 5
= -2

f(x) = ax² + bx + c dengan a=1, b=-2, c=4
f(x) = (1)x² + (-2)x + 4
f(x) = x² - 2x + 4

Semoga membantu