Get the information you need with the help of IDNLearn.com's expert community. Our experts are available to provide accurate, comprehensive answers to help you make informed decisions about any topic or issue you encounter.
Answer:
[tex]\displaystyle f(x) = 3x^2 + 2x + 5\text{ and } g(x) =2x^2 - 4x -2\text{ or } \\ \\ f(x) = 3x^2 + 5 \text{ and } g(x) = x^2 - 4x -2[/tex]
Step-by-step explanation:
We are given the two functions:
[tex]\displaystyle f(x) = 3x^2 + mx +5 \text{ and } g(x) = nx^2 - 4x -2[/tex]
And that:
[tex]\displaystyle h(x) = f(x)\cdot g(x)[/tex]
With the given conditions that (1, -40) and (-1, 24) satisfy the new function, we want to determine functions f and g.
First, find h:
[tex]\displaystyle \begin{aligned} h(x) & = f(x)\cdot g(x) \\ \\ & = (3x^2 + mx +5)(nx^2 - 4x -2) \end{aligned}[/tex]
Because (1, -40) and (-1, 24) are points on the graph of h, we have that h(-1) = 40 and h(-1) = 24. In other words:
[tex]\displaystyle \begin{aligned} h(1) = -40 & = (3(1)^2 + m(1) +5)(n(1)^2 - 4(1) -2) \\ \\ & = (3 + m +5)(n-4 -2) \\ \\ & = (m+8)(n-6) \\ \\ -40 &= mn-6m+8n-48 \end{aligned}[/tex]
And:
[tex]\displaystyle \begin{aligned} h(-1) = 24 & = (3(-1)^2 + m(-1) +5)(n(-1)^2 -4(-1) -2) \\ \\ & = (3 - m +5)(n + 4 -2) \\ \\ & = (-m+8)(n+2) \\ \\ 24 & = -mn -2m + 8n +16 \end{aligned}[/tex]
Solve the system of equations. Adding the two equations together yield:
[tex]\displaystyle -16 = -8m+16n - 32[/tex]
Solve for either m or n:
[tex]\displaystyle \begin{aligned} -16 & = -8m + 16n - 32 \\ \\ 16 & = -8m + 16n \\ \\ 8m & = 16n - 16 \\ \\ m & = 2n -2\end{aligned}[/tex]
Substitute this into one of the two equations above and solve:
[tex]\displaystyle \begin{aligned} -40 & = mn - 6m + 8n - 48 \\ \\ 0 & = (2n-2)n -6 (2n-2) + 8n -8 \\ \\ &= (2n^2 - 2n) + (-12n + 12) +8 n - 8 \\ \\ & = 2n^2 -6n + 4 \\ \\ & = n^2 - 3n + 2 \\ \\ &= (n-2)(n-1) \\ \\ & \end{aligned}[/tex]
Therefore:
[tex]\displaystyle n = 2 \text{ or } n = 1[/tex]
Solve for m:
[tex]\displaystyle \begin{aligned}m &= 2n-2 & \text{ or } m & = 2n-2 \\ \\ & = 2(2) - 1 &\text{ or } & =2(1) -2 \\ \\ &= 2 &\text{ or } & = 0 \end{aligned}[/tex]
Hence, the values of n and m are either: 2 and 2, respectively; or 1 and 0, respectively.
In conclusion, functions f and g are:
[tex]\displaystyle f(x) = 3x^2 + 2x + 5\text{ and } g(x) =2x^2 - 4x -2\text{ or } \\ \\ f(x) = 3x^2 + 5 \text{ and } g(x) = x^2 - 4x -2[/tex]