CSC200 Lab 3

Welcome to CSC200 Lab 3

n! (read n factorial) is given by:
n!=n(n-1)(n-2)...(2)(1).
Factorials grow very large quickly and are thus difficult to find precisely. Sterling's formula is a way to approximate a factorial for large n:

The exp function in the <cmath> header file gives the value of e raised to the given power (see appendix 4 in Savitch or C.5 in Dale/Weems). To compute the absolute value of the difference, you will need the fabs() function. To compute the exponent, use pow(,) and sqrt() for the square root. Compute the value of 15! four ways:

First, directly using a float variable.
Second, directly using a double float variable.
Third, using Stirling's formula in a float variable.
Fourth, using Stirling's formula in a double float variable.
Then calulate the absolute value of the difference beween the float direct and the float Stirling.
Lastly, calulate the absolute value of the difference beween the double float direct and double float Stirling.

The output should appear as follows:

15! (factorial) computed directly with float is:
1307674411008.000000
15! (factorial) computed directly with double float is:
1307674368000.000000

15! (factorial) computed with Sterling's formula as float is:
1300430716928.000000
15! (factorial) computed with Sterling's formula as double float is:
1300430722199.465820

The absolute value of the difference with float is:
7243694080.000000
The absolute value of the difference with double float is:
7243645800.534180

Use 3.141592653589793238462 as your value of Pi and compute the absolute value of the difference.