Question

consider function f defined by f(x) = 4x - 12, x ER Find:a) an expression for f(t+3) b) the image of 3 under f

Answer 1

a) 4t

b) 0

Explanation:

We have the following expression:

`f\mleft(x\mright)=4x-12`

a) We evaluate when x = t + 3, just like this:

`\begin{gathered} f(t+3)=\:4\cdot\left(t+3\right)\:-\:12 \\ \\ f(t+3)=4t+12-12 \\ \\ f(t+3)=4t \end{gathered}`

b) We evaluate when x = 3, just like this:

`\begin{gathered} f(3)=4\cdot3-12 \\ \\ f(3)=12-12 \\ \\ f(3)=0 \end{gathered}`