mcr3u unit 1 test due: september 24th @10:30am app /18 t&i /23 8. the cost function for a telephone…

mcr3u unit 1 test due: september 24th @10:30am app /18 t&i /23 8. the cost function for a telephone manufacturing plant is c(x)=5x + 24 and the revenue function is r(x)=-2x^{2}+27x, where x is the number of telephones sold, in thousands. a) determine the profit function for the number of phones sold. 2t b) determine the number of telephones sold that maximizes profit the maximum profit in thousands. 5t
Answer
Explanation:
Step1: Recall profit - revenue - cost formula
The profit function $P(x)$ is given by $P(x)=R(x)-C(x)$. Given $C(x) = 5x + 24$ and $R(x)=-2x^{2}+27x$.
Step2: Substitute the functions
$P(x)=(-2x^{2}+27x)-(5x + 24)$. $P(x)=-2x^{2}+27x - 5x-24$. $P(x)=-2x^{2}+22x - 24$.
Step3: For part b, find the vertex of the quadratic function
The quadratic function $P(x)=-2x^{2}+22x - 24$ is of the form $y = ax^{2}+bx + c$, where $a=-2$, $b = 22$, and $c=-24$. The $x$ - coordinate of the vertex of a quadratic function $y = ax^{2}+bx + c$ is $x=-\frac{b}{2a}$. $x=-\frac{22}{2\times(-2)}=\frac{22}{4}=5.5$.
Step4: Find the maximum profit
Substitute $x = 5.5$ into the profit function $P(x)$. $P(5.5)=-2\times(5.5)^{2}+22\times5.5 - 24$. $P(5.5)=-2\times30.25+121 - 24$. $P(5.5)=-60.5+121 - 24$. $P(5.5)=36.5$.
Answer:
a) $P(x)=-2x^{2}+22x - 24$ b) The number of telephones sold (in thousands) that maximizes profit is $x = 5.5$, and the maximum profit (in thousands) is $36.5$.