Answer:
The equation in point slope form is [tex]y - 47\,in = \left(-3\,\frac{in}{h}\right)\cdot (t-0\,h)[/tex]
Step-by-step explanation:
Since the swimming pool is being drained at a constant rate, the equation of the process must be a first-order polynomial (linear function), where depth of water decrease as time goes by. The form of the expression is:
[tex]y = m \cdot t + b[/tex]
Where:
[tex]t[/tex] - Time, measured in hours.
[tex]b[/tex] - Initial depth of the water in swimming pool (slope), measured in inches.
[tex]m[/tex] - Draining rate, measured in inches per hour.
[tex]y[/tex] - Current depth of the water in swimming pool (x-Intercept), measured in inches.
If [tex]m = -3\,\frac{in}{h}[/tex] and [tex]y (5\,h) = 32\,in[/tex], the initial depth of the water in swimming pool is:
[tex]b = y - m\cdot t[/tex]
[tex]b = 32\,in -\left(-3\,\frac{in}{h} \right)\cdot (5\,h)[/tex]
[tex]b = 47\,in[/tex]
The equation in point slope form is:
[tex]y-y_{o} = m \cdot (t-t_{o})[/tex]
Where [tex]y_{o}[/tex] and [tex]t_{o}[/tex] are initial depth of the water in swimming pool and initial time, respectively. Then, the equation in point slope form is:
[tex]y - 47\,in = \left(-3\,\frac{in}{h}\right)\cdot (t-0\,h)[/tex]
