Working with Exponents in c++ I'm an automotive hobbyist and an intermediate coder. I seem to lack a fundamental understanding of the arithmetic when working with the exponent formula in excel or the math.exp() method in c++.
I have a vendor datasheet which describes a formula to resolve the resistance of a thermistor for any given temperature.
Trying to solve for x, the datasheet gives this: x = exp{A + B/T + C/T2 + D/T3}
where T is the temperature in Kelvin.
note the brackets as opposed to parenthesis.
The datasheet provides values for A, B, & C at various Kelvin ranges
For instance, at 283.15K (50 F), per the datasheet chart;
A is -16.2931
B is 6061.2476
C is -460567.9092
D is 30338541.7656
It doesn't look like a simple matter of (A + B/T + C/T2 + D/T3). Excel's EXP() formula rejects this as too big of a number, running it to a consol.output(result) in C++ calls it infinity.  (The brackets {} must mean something other than what parenthesis mean, right?), but what?
How should x be resolved?
Thanks
edit: snapshot of datasheet

 A: When I perform the numerical calculation with the proposed coefficients, the result is $2.024$ which is not at all out of range, so the formula may well be the correct one.
My guess would rather be a typo in your written code ?
Example C++ code
A: If the vendor gives for a given range of $T$ the formula
$$x=\exp\Bigg[A+\frac{B}{T}+\frac{C}{T^2}+\frac{D}{T^3}\Bigg]\qquad \text{for} \quad T_1\leq T \leq T_2$$ I stronly suppose that for a given $T$, there is only one $x$.
So, each formula can be analytically inversed for the given range and this has to be done only once. So, at each equation corresponds an analytical inverse in the form
$$T=f(x)\qquad \text{for} \quad x_1\leq x \leq x_2$$
Using the second curve as @zwim did, there are three roots but only one is acceptable. Using the trigonometric method with whole numbers and defining
$$p=\frac{29257638226710183955}{1917556492631365761132}$$
$$q=-\frac{1250 }{37923177207}\log
   (x)-\frac{33865607624057288640109707563}{4363190080469560409150476
   13509944}$$ we have
$$ T=\frac 1{2 \sqrt{\frac{p}{3}} \cos \left(\frac{1}{3} \cos ^{-1}\left(-\frac{3 \sqrt{3} q}{2   p\sqrt p}\right)\right)+\frac{383806591}{75846354414}}$$ for $0.35072 \leq x \leq 3.36287$
