how to calculate exp(x) [closed]

Could someone explain me how to calculate "exp"?

Basically I have to calculate intrinsic density for silicon at T = 200K $$n_i=(N_cN_v)^{1/2}exp(-\frac{E_G}{2E_T})[cm^{-3}]$$

$$\sqrt{N_c N_v}=1.3173\times10^{19}$$ $$E_G=1.14736$$ $$-\frac{E_G}{2E_T}=-33.35$$

I need to calculate $exp(-33.35)$

How can I calculate $exp(x)$?

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Nothing to do with electronic design. Question should be closed. – Leon Heller Apr 19 '12 at 22:28
yea I know, but I'm SO user and hoped I might get some help here, as this has nothing to do with programming :/ – Tensio Apr 19 '12 at 22:30
Maybe try math.stackexchange.com – Kris Bahnsen Apr 19 '12 at 22:31
Um, calculator? Am I missing something? – AngryEE Apr 19 '12 at 22:34
yep, it's a function and if I calculate exp(x) using wolframalpha I get correct solution but what does that function stands for and how can I calculate it using calculator? – Tensio Apr 19 '12 at 22:41
$exp(x)$ can also be written as $e^x$. Most scientific/graphing calculators will have this as a function. The number e is a constant irrational number approximately equal to 2.71828183.
 yep it works, Thanks a lot :) – Tensio Apr 19 '12 at 22:45 On Windoze calculator it's inv ln – Federico Russo Apr 20 '12 at 14:19 @FedericoRusso So clever with the "Windoze". – W5VO♦ Apr 20 '12 at 15:10