So I got these problems and we didn't go over this in class.

What value of x will give the minimum value for 9x^2 + 18x + 7?

Help please?

WhichWitchIsWhich
Oct 23, 2017

#1**+1 **

The x value that gives the minimum or maximum value for a quadratic function,

ax^{2} + bx + c , is - \(\frac{b}{2a}\) .

So for this one...

The x value that gives the minimum or maximum value for

9x^{2} + 18x + 7 is - \(\frac{18}{2(9)}\) = - 1 .

And in this case, 9 is positive, so the parabola opens upward, and we have a minimum.

hectictar
Oct 23, 2017

#1**+1 **

Best Answer

The x value that gives the minimum or maximum value for a quadratic function,

ax^{2} + bx + c , is - \(\frac{b}{2a}\) .

So for this one...

The x value that gives the minimum or maximum value for

9x^{2} + 18x + 7 is - \(\frac{18}{2(9)}\) = - 1 .

And in this case, 9 is positive, so the parabola opens upward, and we have a minimum.

hectictar
Oct 23, 2017