For a number (a), find (x) such that (a cdot x = 1)
For a fraction (frac{p}{q}), the multiplicative inverse is (frac{q}{p})
For an integer (a), the multiplicative inverse is (frac{1}{a})
For a nonzero number modulo (m), find (x) such that (a x equiv 1 pmod m)
Use the Extended Euclidean Algorithm to find the modular inverse when (gcd(a,m)=1)
Check that the inverse exists only if the number is nonzero
Check that the modular inverse exists only if (gcd(a,m)=1)