The function [tex]$F(x)=\frac{9}{5} x+32$[/tex] models the temperature in degrees Fahrenheit, given the temperature [tex]$x$[/tex] in degrees Celsius.

Part A
Which expression models [tex][tex]$F^{-1}$[/tex][/tex]?
A. [tex]$\frac{5}{9} x-32$[/tex]
B. [tex]$\frac{5}{9}(x+32)$[/tex]
C. [tex][tex]$\frac{9}{5} x-32$[/tex][/tex]
D. [tex]$\frac{5}{9}(x-32)$[/tex]

Part B
What is the value of [tex]$F^{-1}(50)$[/tex] and what does it represent?
Select from the drop-down lists to correctly complete the sentence.

The value is [tex][tex]$\square$[/tex][/tex] and it represents the temperature in degrees [tex]$\square$[/tex] when the temperature is 50 [tex]$\square$[/tex].



Answer :

Let's go through this problem step-by-step.

### Part A
We need to find the inverse function [tex]\( F^{-1}(x) \)[/tex]. We're given the function:
[tex]\[ F(x) = \frac{9}{5}x + 32 \][/tex]

To find the inverse function [tex]\( F^{-1}(x) \)[/tex], we will perform the following steps:

1. Start with the equation [tex]\( y = F(x) \)[/tex]:
[tex]\[ y = \frac{9}{5}x + 32 \][/tex]

2. Swap the variables [tex]\( y \)[/tex] and [tex]\( x \)[/tex]:
[tex]\[ x = \frac{9}{5}y + 32 \][/tex]

3. Solve for [tex]\( y \)[/tex]:
[tex]\[ x - 32 = \frac{9}{5}y \][/tex]
[tex]\[ y = \frac{5}{9}(x - 32) \][/tex]

So the inverse function [tex]\( F^{-1}(x) \)[/tex] is:
[tex]\[ F^{-1}(x) = \frac{5}{9}(x - 32) \][/tex]

Comparing with the given choices, the correct expression that models [tex]\( F^{-1}(x) \)[/tex] is:
[tex]\[ \frac{5}{9}(x-32) \][/tex]

### Part B
Next, we need to determine the value of [tex]\( F^{-1}(50) \)[/tex] and interpret its significance.

Plugging [tex]\( x = 50 \)[/tex] into the inverse function:
[tex]\[ F^{-1}(50) = \frac{5}{9}(50 - 32) \][/tex]

We already know from the result:
[tex]\[ F^{-1}(50) = 10.0 \][/tex]

So, the value of [tex]\( F^{-1}(50) \)[/tex] is [tex]\( 10.0 \)[/tex].

This value represents the temperature in degrees Celsius when the temperature is 50 degrees Fahrenheit.

To complete the sentence:
The value is 10.0 and it represents the temperature in degrees Celsius when the temperature is 50 degrees Fahrenheit.