Question

which funtion has the largest value for f(-3)?. f(x)=2-4x. f(x)=2x-5. f(x)=6-3^x. f(x)=2^×+10

Answer 1

The notation f(-3) indicates that you have to calculate the value of the function f(x) for x=3.

To determine which value has the largest value for f(-3) you have to replace each function with x=3 and calculate the corresponding value of f(x)

1.

$\begin{gathered} f(x)=2-4x \\ f(-3)=2-4(-3) \\ f(-3)=2-(-12) \\ f(-3)=2+12 \\ f(-3)=14 \end{gathered}$

2.

$\begin{gathered} f(x)=2x-5 \\ f(-3)=2\cdot(-3)-5 \\ f(-3)=-6-5 \\ f(-3)=-11 \end{gathered}$

3.

$\begin{gathered} f(x)=6-3^x \\ f(-3)=6-3^{-3} \\ f(-3)=\frac{161}{27} \\ f(-3)\approx5.92 \end{gathered}$

4.

$\begin{gathered} f(x)=2^x+10 \\ f(-3)=2^{-3}+10 \\ f(-3)=\frac{81}{8} \\ f(-3)\approx10.125 \end{gathered}$

Now that we calculated f(-3) for each one of the functions, you can compare them.

The function that has the largest value of f(-3) is the first one: f(x)=2-4x