Question

A function is shown below :

what is f(3)?

Please explain if possible!! Thank you!!

Answer 1

Given:

`f(x)=\begin{cases}-(1)/(2)x^2 & 0<x\leq 3 \\ x^3+2x & x>3\end{cases}`

To find:

The value of f(3).

Explanation:

For x=3, we have

`f(x)=-(1)/(2)x^2`

Putting x=3 in the above function, we get

`f(3)=-(1)/(2)(3)^2`

`f(3)=-(1)/(2)(9)`

`f(3)=-(9)/(2)`

Therefore, the value of f(3) is
`-(9)/(2)`. So, the correct option is a.