Let [tex]$f(x)=\frac{8}{1+3 e^{-0.7 x}}$[/tex].

What is the value of [tex]$f(-3)$[/tex]?

Round the answer to the nearest hundredth.

Enter your answer in the box.
[tex]\square[/tex]



Answer :

To find the value of the function [tex]\( f(x) = \frac{8}{1 + 3 e^{-0.7 x}} \)[/tex] at [tex]\( x = -3 \)[/tex], follow these steps:

1. Substitute [tex]\( x = -3 \)[/tex] into the function:
[tex]\[ f(-3) = \frac{8}{1 + 3 e^{-0.7 (-3)}} \][/tex]

2. Simplify the exponent:
[tex]\[ -0.7 \times (-3) = 2.1 \][/tex]
Therefore,
[tex]\[ f(-3) = \frac{8}{1 + 3 e^{2.1}} \][/tex]

3. Calculate [tex]\( e^{2.1} \)[/tex]:
The value of the exponential function [tex]\( e^{2.1} \approx 8.1662 \)[/tex].

4. Substitute [tex]\( e^{2.1} \)[/tex] back into the function:
[tex]\[ f(-3) = \frac{8}{1 + 3 \times 8.1662} \][/tex]

5. Multiply and add:
[tex]\[ 3 \times 8.1662 = 24.4986 \][/tex]
[tex]\[ 1 + 24.4986 = 25.4986 \][/tex]

6. Divide:
[tex]\[ f(-3) = \frac{8}{25.4986} \approx 0.31374382590567385 \][/tex]

7. Round the result to the nearest hundredth:
[tex]\[ f(-3) \approx 0.31 \][/tex]

Therefore, the value of [tex]\( f(-3) \)[/tex] rounded to the nearest hundredth is:
[tex]\[ 0.31 \][/tex]