Pre-Calculus Summary Calculator

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Factorials

n! is defined as n x (n - 1) x (n - 2) x ... x 2 x 1
5! = 120 shown here

Permutations and Combinations

Permutations are the number of ways you can choose r items from a total of n items (uniqueness not required)

nPr  =	n!
	(n - r)!

₁₂P₅ = 95,040 shown here

Combinations are the number of ways you can choose r unique items from a total of n items

nCr  =	n!
	r!(n - r)!

₁₂C₅ = 792 shown here

Logarithms:

Logarithms are defined by the equation Log a_b = e
Log 1000_b = 3, we get b = 10 shown here
Log(ab) = Log(a) + Log(b)
Log(x/y) = Log(x) - Log(y)