SOLUTION: Please please help
Find the quadraic equation that fits the following set of data points
(5,9),(4,-45),(-1,-15)
Algebra.Com
Question 456616: Please please help
Find the quadraic equation that fits the following set of data points
(5,9),(4,-45),(-1,-15)
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
Find the quadratic equation that fits the following set of data points
(5,9),(4,-45),(-1,-15)
:
Using the form: a^2 + b^2 + c^2 = y, write an equation for each ordered pair
:
5,9
5^2a + 5b + c = 9
25a + 5a + c = 9
:
4,-45
16a + 4b + c = -45
:
-1,-15
1a - 1b + c = -15
:
You can solve this as a 3X4 matrix
25 5 1 9
16 4 1 -45
1 -1 1 -15
:
but you can also use elimination/substitution, which will take longer
:
Subtract the 2nd equation from the 1st equation
25a + 5b + c = 9
16a + 4b + c = -45
------------------------eliminates c
9a + b = 54
for substitution
b = (54-9a)
:
Subtract the 3rd equation from the 1st equation
25a + 5b + c = 9
1a - 1b + c = -15
------------------------eliminates c again
24a + 6b = 24
Replace b with (54-9a)
24a + 6(54-9a) = 24
24a + 324 - 54a = 24
24a - 54a = 24 - 324
-30a = -300
a = +10
find b
b = 54 - 9(10)
b = 54 - 90
b = -36
:
Use the 1st equation to find c
25(10) + 5(-36) + c = 9
250 - 180 + c = 9
70 + c = 9
c = 9 - 70
c = -61
:
The equation for these ordered pairs, y = 10x^2 - 36x - 61
:
I confirmed this using the matrix feature on my calc.
:
RELATED QUESTIONS
Find the quadratic Equation that fits the following set of Data points.... (answered by ankor@dixie-net.com)
find a quadratic function that fits the set of data points (2,0) (4,3)... (answered by ewatrrr)
Find a quadratic function that fits the set of data points:... (answered by ankor@dixie-net.com)
heres the question: FInd a quadration function that fits the set of data points... (answered by ankor@dixie-net.com)
I am having a hard time with quadratic equations, can someone help me.
Find the... (answered by jim_thompson5910)
find a quadratic function that fits each set of data points
(-1, 4) ( 0,4) (4,84) (answered by stanbon)
still stuck, please help
Find the quadratic equation that fits the following set of... (answered by Edwin McCravy)
Find the quadratic function that fits the set of data points.
(-3,-5), (-2,-8),... (answered by stanbon)
you provide great, can someone help me with these problems
Find all x intercepts of... (answered by stanbon)