Quadratic functions

[rachelmaddie]

I need my work checked for this please.
The quadratic function of the form is: ax^2 + bx + c
where a, b, and c are the coefficients

The function has a maximum value if a < 0
The function has a minimum value if a > 0

The maximum or minimum value will always be at the point.
x = - b/2a
= f(-b/2a)

The function is f(x) = -5^2 -10x + 6

Note that a = -5, a < 0

The maximum is at the point:
x = - (-10)/2(-5)
x = -1
y = f(-1)
y = -5(-1)^2 - 10 (-1) + 6
y = 11
The maximum value of the function is f(-1) = 11

 

[yoscar04]

Your answer is correct. You just forgot to write y in your equation y=f(-b/2a).

 

[rachelmaddie]

Your answer is correct. You just forgot to write y in your equation y=f(-b/2a).

The quadratic function of the form is: ax^2 + bx + c
where a, b, and c are the coefficients

The function has a maximum value if a < 0
The function has a minimum value if a > 0

The maximum or minimum value will always be at the point.
x = - b/2a
y = f(-b/2a)

The function is f(x) = -5^2 -10x + 6

Note that a = -5, a < 0

The maximum is at the point:
x = - (-10)/2(-5)
x = -1
y = f(-1)
y = -5(-1)^2 - 10 (-1) + 6
y = 11
The maximum value of the function is f(-1) = 11

You mean like this?

 

[yoscar04]

yap.