SOLUTION: what is the equation of the quadratic function described of the minimum value of f is f(3)= -5 and f(1) = 2

Algebra.Com
Question 210791: what is the equation of the quadratic function described of the minimum value of f is f(3)= -5 and f(1) = 2
Answer by scott8148(6628)   (Show Source): You can put this solution on YOUR website!
the minimum lies on the axis of symmetry, so f(5) = f(1) = 2

f(x) = ax^2 + bx + c

f(1) = a(1^2) + b(1) + c ___ 2 = a + b + c ___ 2 - a - b = c

f(3) = a(3^2) + b(3) + c ___ -5 = 9a + 3b + c
substituting ___ -5 = 9a + 3b + 2 - a - b ___ -7 = 8a + 2b ___ -14 = 16a + 4b

f(5) = a(5^2) + b(5) + c ___ 2 = 25a + 5b + c
substituting ___ 2 = 25a + 5b + 2 - a - b ___ 0 = 24a + 4b

subtracting equations ___ 14 = 8a ___ 7/4 = a

substituting ___ 0 = 24(7/4) + 4b ___ -42 = 4b ___ -21/2 = b

substituting ___ 2 - 7/4 - -21/2 = c ___ 43/4 = c

f(x) = (7/4)x^2 - (21/2)x + 43/4

RELATED QUESTIONS

Find the vertex, the line of symmetry, the maximum or minimum value of the quadratic... (answered by lwsshak3)
find a quadratic equation where f(2)=16 and the minimum value of f is... (answered by stanbon)
Find the vertex, the line of symmetry, the maximum or minimum value of the quadratic... (answered by Earlsdon)
Find the vertex, the line of symmetry, and the maximum or minimum value of f(x). Graph... (answered by ewatrrr)
If the minimum value of f(x) is (3,-1), and g(x)=f(x-2)+5, what is the minimum value of... (answered by jim_thompson5910)
Find the vertex, the line of symmetry, the maximum or minimum value of the quadratic... (answered by solver91311)
What does it mean when it says "find the quadratic equation where f(1)=2 and the maximum... (answered by Fombitz)
A sinusoidal function whose period is 12 , maximum value is 10, and minimum value is... (answered by greenestamps)
Find the vertex, the line of symmetry, the maximum or minimum value of the quadratic... (answered by Earlsdon)