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
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   a  - b  +  c = 10
                  c = 5
4 a + 2 b + c = 13
------------------------
    a - b +5 = 10
4 a  + 2 b + 5 = 13
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   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