Question 459636: you provide great, can someone help me with these problems
Find all x intercepts of the given f(x) =-9sqrt x + 18
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Find the quadratic equatioin that fits the following set of data points
((3,66),(-4,38),(-1-10))
Thank you
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Find all x intercepts of the given f(x) = -9sqrt x + 18
y = 0 for all x-intercepts
Solve -9x^2+18 = 0
Divide thru by -9 to get:
x^2-2 = 0
x^2 = 2
x = +/-sqrt(2)
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Find the quadratic equation that fits the following set of data points
((3,66),(-4,38),(-1-10))
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Form: ax^2 + bx + c = y
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Substitute for (x,y) and solve for a,b,c:
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Using (3,66): 9a + 3b + c = 66
Using(-4,38): 16a- 4b + c = 38
Using(-1,-10):: a - b + c = -10
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Use any method you know to solve the system to get:
a = 5
b = 9
c = -6
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Equation: y = 5x^2+9x-6
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Cheers,
Stan H.
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