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Mathematics Clinic => Grade 9 Mathematics => Topic started by: geoffrey on Oct 4, 2013

Title: How can I rearrange this formula 1/R=A e -B/T to find the constant e and the other constant B?
Post by: geoffrey on Oct 4, 2013

I'm conducting this thermometer experiment with the thermistor. I recorded the values on the voltmeter and the ammeter then found the resistance of the thermometer. I was then asked to plot an appropriate graph that would help to determine the constants e and B. I'm terrible at transposing formulas so if someone transpose the above formula, I will be able to continue from there. PLEASE HELP!!!!

Title: How can I rearrange this formula 1/R=A e -B/T to find the constant e and the other constant B?
Post by: Hawke on Oct 4, 2013

e is a constant.

To solve for B, first divide by A,

1/RA = e^(-BT)

Then take the natural log,

ln(1/RA) = -BT

Divide by -T,

-1/T ln(1/RA) = B

EDIT: If you want to plot a graph and solve this graphically instead of analytically, you'll first need to plug in your data and then try to use a best fit curve to approximate a trend. From there, based on the equation of that curve, you can determine B. I recommend Graphical Analysis for this - it's a fairly easy program to use and it can fit a variety of curves, without being overly complicated.