Chapter 1.3, Problem 43E

To determine

To find: $f\left(9\right)$ , if $f\left(x\right)=4+6x-x^3$

Answer to Problem 43E

  $-671$

Explanation of Solution

Given information: The given function is $f\left(x\right)=4+6x-x^3$ .

Calculation:

To find $f\left(9\right)$ , substitute the value of x = 9, in the given function and simplify it as shown below.

  $\begin{array}{c}f\left(x\right)=4+6x-x^3\\ f\left(9\right)=4+6\left(9\right)-{\left(9\right)}^3\\ =4+54-729\\ =-671\end{array}$

Thus, the function $f\left(x\right)$ is $-671$ .