Do the following for the points 41022231 If you are entering
Do the following for the points (4,1),(0,2),(2,2),(3,1) (If you are entering decimal approximations, enter at least five decimal places.)
(a) Find the equation for the best-fitting parabola
(b) Find the equation for the best-fitting parabola with no constant term y=ax2+bx
(c) Find the equation for the best-fitting parabola with no linear term y=ax2+cy=ax2+c for these points:
Solution
a). equation of parabola y= ax^2 +bx +c
points are (4,1),(0,2),(2,2),(3,1)
(0,2)
2 = 0 +0+c
so c=2
y = ax^2 + bx+2
(2,2)
2 = 4a +2b +2
4a+2b=0
2a =-b
(3,-1)
-1 = 9a +3b +2
-3 = 9a + 3(-2a)
-3 =9a-6a
3a=-3
a=-1
2 =b
y = -x^2 +2x+2
b).
y=ax2+bx
(4,1),(0,2),(2,2),(3,1) points
(-4,-1)
-1 = 16a -4b
2= 4a +2b
2a+b =1
b = 1-2a
16a -4(1-2a) =-1
16a-4+8a=-1
24a = 3
a=1/8
b =1-2a = 1-2/8
=3/4


