When the Celsius temperature is 15degrees​, the corresponding Fahrenheit temperature is 59degrees. When the Celsius temperature is 75degrees​, the corresponding Fahrenheit temperature is 167 degrees . Let C represent the Celsius temperature and F the Fahrenheit temperature.a. Express F as an exact linear function of C.b. Solve the equation in part a for​ C, thus expressing C as a function of F.c. For what temperature is Fequals​C?

Respuesta :

Answer:

(a) [tex]F=1.8C+32[/tex]

(b) [tex]C=\frac{F-32}{1.8}[/tex]

(c) -40 degree

Step-by-step explanation:

(a)

A linear function is of the form [tex]y=mx+b[/tex]

Given:

Temperature in Fahrenheit is given as 'F' and in Celsius is 'C'.

So, the linear relation is of the form [tex]F = mC + b[/tex], where, 'm' and 'b' are real numbers.

Now, when [tex]C=15,F=59[/tex]

When [tex]C=75,F=167[/tex]

Now, plugging these values in the above equation and solving for 'm' and 'b', we have:

[tex]59=15m+b\\167=75m+b\\(-)\\---------- \\-108=-60m\\\\m=\frac{108}{60}=1.8[/tex]

Now, plugging 'm' value in first equation to get 'b' value, we have:

[tex]b=59-15\times 1.8=32[/tex]

Therefore, the equation expressed for 'F' in terms of 'C' is given as:

[tex]F=1.8C+32[/tex]

(b)

In order to solve for 'C', we isolate 'C' from the above equation.

Add -32 both sides. This gives,

[tex]F-32=1.8C[/tex]

Divide both sides by 1.8. This gives,

[tex]C=\frac{F-32}{1.8}[/tex]

Therefore, the equation solved for 'C' is [tex]C=\frac{F-32}{1.8}[/tex]

(c)

Let the temperature be 'x' when F = C.

Therefore, [tex]F = x, C = x[/tex]

[tex]x=\frac{x-32}{1.8}\\\\1.8x=x-32\\\\1.8x-x=-32\\\\0.8x=-32\\\\x=\frac{-32}{0.8}=-40[/tex]

Therefore, at -40 degree, the temperature in Fahrenheit equals that in Celsius.