# What is the inverse of modulo?

## What is the inverse of modulo?

The modular inverse of A mod C is the B value that makes A * B mod C = 1. Simple!

What is the inverse of 4 modulo 5?

For example, the modular inverses of 1, 2, 3, and 4 (mod 5) are 1, 3, 2, and 4.

What is the inverse of 7 mod 26?

So, the inverse of 15 modulo 26 is 7 (and the inverse of 7 modulo 26 is 15). Gcd(6, 26) = 2; 6 and 26 are not relatively prime.

### What is the inverse of 7?

Dividing by a number is equivalent to multiplying by the reciprocal of the number. Thus, 7 ÷7=7 × 1⁄7 =1. Here, 1⁄7 is called the multiplicative inverse of 7.

What is the inverse of 19 MOD 141?

52
Therefore, the modular inverse of 19 mod 141 is 52. Again we end up with something in the form 1 = sa+tm = 52(19)−7(141) making our inverse 52.

What is the inverse of 5 mod 7?

t3 = 6 is the modular multiplicative inverse of 5 × 7 (mod 11).

#### What is the multiplicative inverse of 4 7?

i.e, multiplicative inverse of 4/7 is 7/4.

What are multiplicative inverse of 7?

Are 19 and 141 relatively prime?

Therefore, 141 and 19 are relatively prime and 19 mod 141 has an inverse.

## How to find the modular inverse of mod c?

A naive method of finding a modular inverse for A (mod C) is: step 1. Calculate A * B mod C for B values 0 through C-1 step 2. The modular inverse of A mod C is the B value that makes A * B mod C = 1 Note that the term B mod C can only have an integer value 0 through C-1, so testing larger values for B is redundant.

Which is the modular inverse of an integer?

In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that a x ≡ 1 ( mod m ) . {\\displaystyle a\\,x\\equiv 1 {\\pmod {m}}.} Or in other words, such that: It can be shown that such an inverse exists if and only if a and m are coprime, but we will ignore this for this task.

Which is modulo inverse of 10 under 17?

Input: a = 10, m = 17 Output: 12 Since (10*12) mod 17 = 1, 12 is modulo inverse of 10 (under 17). Recommended: Please solve it on “ PRACTICE ” first, before moving on to the solution.

### Which is the best modular multiplicative inverse algorithm?

Modular multiplicative inverse 1 Naive Method, O (m) 2 Extended Euler’s GCD algorithm, O (Log m) [Works when a and m are coprime] 3 Fermat’s Little theorem, O (Log m) [Works when ‘m’ is prime]