The power, in megawatts, produced between midnight and noon by a power plant is given by [tex]P = h^2 - 12h + 210[/tex], where [tex]h[/tex] is the hour of the day.

a. At what time does the minimum power production occur?
b. What is the minimum power production?



Answer :

To determine when the minimum power production occurs and what the minimum power production is, we need to analyze the given quadratic function [tex]\( P = h^2 - 12h + 210 \)[/tex], which represents the power produced in megawatts, where [tex]\( h \)[/tex] is the hour of the day.

### Step-by-Step Solution:

1. Identify the Form of the Quadratic Equation:

The given function [tex]\( P = h^2 - 12h + 210 \)[/tex] is a quadratic equation of the form [tex]\( P = ah^2 + bh + c \)[/tex] where:
- [tex]\( a = 1 \)[/tex]
- [tex]\( b = -12 \)[/tex]
- [tex]\( c = 210 \)[/tex]

2. Determine the Vertex of the Parabola:

For a quadratic equation [tex]\( ah^2 + bh + c \)[/tex], the vertex represents the maximum or minimum point of the parabola. To locate the vertex, we use the formula for the hour [tex]\( h \)[/tex] at which this occurs:
[tex]\[ h_{\text{min}} = -\frac{b}{2a} \][/tex]
Substituting in the values of [tex]\( a \)[/tex] and [tex]\( b \)[/tex]:
[tex]\[ h_{\text{min}} = -\frac{-12}{2 \times 1} = \frac{12}{2} = 6 \][/tex]

3. Evaluate the Minimum Power Production:

Having determined that the minimum power production occurs at [tex]\( h = 6 \)[/tex], we need to calculate [tex]\( P \)[/tex] at this hour by substituting [tex]\( h = 6 \)[/tex] back into the original quadratic equation:
[tex]\[ P = (6)^2 - 12(6) + 210 \][/tex]
Calculate each term step-by-step:
[tex]\[ 6^2 = 36 \][/tex]
[tex]\[ 12 \times 6 = 72 \][/tex]
[tex]\[ P = 36 - 72 + 210 \][/tex]
[tex]\[ P = -36 + 210 \][/tex]
[tex]\[ P = 174 \][/tex]

Thus, the minimum power production occurs at [tex]\( h = 6 \)[/tex] hours, which is 6:00 AM, and the minimum power produced is [tex]\( 174 \)[/tex] megawatts.