Question

If f(x) = 3x and g(x) = 7x-1, what is (fog)(4)?

Answer 1

Answer:

83

Step-by-step explanation:

solution:

we have

f(x)= 3x & g(x)= 7x-1

now

fog= f{g(x)}

or, f(7x-1)

or, 7.3x-1 = 21x-1

so, fog(4)= 21*4-1=84-1=83

Answer 2

The composite function  $(fog)(4)$  has a value = 81, given $f(x) = 3x$, and $g(x) = 7x - 1$ .

What is a composite function?

$f(g(x))$ or  $(fog)(x)$ represents the aggregate of functions f(x) and g(x), wherein g(x) acts first. It is a function that combines more functions to supply some other function. The output of one function inside the parenthesis will become the input of the outer function in composite functions. i.e.,

$g(x)$ is the input of $f(x)$ in $f(g(x))$.

$f(x)$ is the input of $g(x)$ in $g(f(x))$.

How do we solve the given question?

We are given functions:

$f(x) = 3x$

$g(x) = 7x - 1.$

We are asked to discover the value of the composite function $(f o g)(4)$

Now we know, $(fog)(4) = f(g(4))$

We first discover the value $g(4)$ with the aid of using substituting $x = 4$ in $g(x)$.

∴  $g(4) = 7(4) - 1 = 28 - 1 = 27$.

Now, we use the value of $g(4) = 27$, in $f(x)$ to compute the value of $f(g(4))$.

∴ $f(g(4)) = f(27)$.

To discover $f(27)$ , we substitute $x = 27$ in $f(x)$

∴ $f(27) = 3(27) = 81$.

∴ The composite function $(fog)(4) = 81$, given $f(x) = 3x$, and $g(x) = 7x - 1$.

Learn more about composite functions at

brainly.com/question/10687170

#SPJ2