Question

16. What is the equation, in standard form, of a parabola that models the values in the table?

x –1 0 2
f(x) 10 5 13

y = 3x2– 2x + 5
y = x2– 2x + 5
y = 2x2– 3x + 5
y = –3x2+ 2x + 5

Answer 1

a x² + b x + c = y
--------------------------
a - b + c = 10
c = 5
4 a + 2 b + c = 13
------------------------
a - b +5 = 10
4 a + 2 b + 5 = 13
--------------------------
a - b = 5 / * 2
4 a + 2 b = 8
------------------
2 a - 2 b = 10
+
4 a + 2 b = 8
----------------------
6 a = 18
a = 18 : 6
a = 3
3 - b = 5
b = - 2
Answer:
B ) y = 3 x² - 2 x + 5