We are given the following functions:
![\begin{gathered} f\mleft(x\mright)=2x+1,\text{ and} \\ g\mleft(x\mright)=3x^2-1 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/7lf7ifkx1n46fn967tby4j9gwkca85su79.png)
We are asked to determine the following:
![(f\circ g)(x)](https://img.qammunity.org/2023/formulas/mathematics/high-school/q2jaqr9ioobwh5yqddx52oo1tt6s8hbyab.png)
This is a composition of functions and it is equivalent to the following:
![(f\circ g)(x)=f(g(x))](https://img.qammunity.org/2023/formulas/mathematics/college/qytlfzimoxtv7qpo9rm3ru8joolfgz0nxs.png)
This means that we will substitute the value of "x" is f(x) for the function g(x), like this:
![f(g(x))=2(3x^2-1)+1](https://img.qammunity.org/2023/formulas/mathematics/college/8mfc8wev6jpqrnbm9tns5jb4py8dr42plw.png)
Now we simplify, first by applying the distributive property:
![f(g(x))=6x^2-2+1](https://img.qammunity.org/2023/formulas/mathematics/college/qq4qnvmr443o42xwfxqpoxyaf4zkqyd9ht.png)
Now we solve the operation:
![f(g(x))=6x^2-1](https://img.qammunity.org/2023/formulas/mathematics/college/3g0669odozjfjfbpfd0r66zt2ywcauax9z.png)
And thus we have the composition of the functions.
For part B we are asked:
![(g\circ f)(x)=g(f(x))](https://img.qammunity.org/2023/formulas/mathematics/college/8lu2o6klwimn8usrejj4tq4ax3gg3hc8p3.png)
This means that this time we will substitute the value of "x" in g(x) for the function f(x), like this:
![g(f(x))=3(2x+1)^2-1](https://img.qammunity.org/2023/formulas/mathematics/college/zupn8jejkdinlndag3nl5l7120m3lwt2qs.png)
Now we simplify the function. First, we solve the square using the following relationship:
![(a+b)^2=a^2+2ab+b^2](https://img.qammunity.org/2023/formulas/mathematics/high-school/4wp4nbc9fbx6r68qmr14kcon9sub55nk8b.png)
Using the relationship we get:
![g(f(x))=3(4x^2+4x+1)-1](https://img.qammunity.org/2023/formulas/mathematics/college/48dj224gzvenc9qgtax2ir4she6m0xdks7.png)
Now we apply the distributive property:
![g(f(x))=12x^2+12x+3-1](https://img.qammunity.org/2023/formulas/mathematics/college/83tbfhlyq8hmykz9eh1vlkjsly3v98g496.png)
Now we solve the operations:
![g(f(x))=12x^2+12x+2](https://img.qammunity.org/2023/formulas/mathematics/college/u1104xfzpe1f9gh3raa3llo7ptmlbnegl2.png)
And thus we get the composition of the functions.