# changing celsius to F

• Sep 17th 2012, 03:19 PM
Louisana1
changing celsius to F
45.7°f = what in celsius

Is this the equation I should be using

C = °F-32/1.8
C= 45.7-32/1.8= 7.6
• Sep 17th 2012, 03:45 PM
skeeter
Re: changing celsius to F
check it yourself ...

Fahrenheit to Celsius Converter
• Sep 17th 2012, 04:12 PM
emakarov
Re: changing celsius to F
Quote:

Originally Posted by Louisana1
Is this the equation I should be using

C = °F-32/1.8
C= 45.7-32/1.8= 7.6

The equation is wrong as written, though the answer 7.6 is (approximately) correct.
• Sep 20th 2012, 02:01 AM
kraj8995
Re: changing celsius to F
Your answer is correct but the correct equation for Fahrenheit to Celsius is :
(F - 32) x 5/9 = C
where F=45.7
Thus,
(45.7-32)*5/9=7.6

Composition of Functions
• Sep 20th 2012, 02:14 AM
MarkFL
Re: changing celsius to F
To derive the formula, use the freezing and boiling points of water, to get the slope of the line:

$\displaystyle \frac{\Delta C}{\Delta F}=\frac{100-0}{212-32}=\frac{5}{9}$

Now, use the point-slope formula:

$\displaystyle C-0=\frac{5}{9}(F-32)$

$\displaystyle C(F)=\frac{5}{9}(F-32)$
• Sep 20th 2012, 06:31 AM
HallsofIvy
Re: changing celsius to F
Quote:

Originally Posted by Louisana1
45.7°f = what in celsius

Is this the equation I should be using

C = °F-32/1.8
C= 45.7-32/1.8= 7.6

You mean C= (F- 32)/1.8. What you wrote really means C= F- (32/1.8)
You can check that is correct by checking the "easy values". The freezing point of water is 0 C and 32F:
(32-32)/1.8= 0/1.8= 0 so that is correct.
The boiling point of water is 100 C and 212 F:
(212- 32)/1.8= 180/1.8= 100 so that is correct.

Since this is a "linear" equation and two points determine a line you know that is the correct formula for any F.