Solving quadratic congruence

Question

I want to solve this equation x^2= 4 mod 3 in R, I tried many commands but that commands are not related to this equation. Please help me to find the command. For example, I tried

modlin(2,4,3)
# [1] 2

modpower(2,4,3)
# [1] 1

and five other commands.

this should help you. https://stat.ethz.ch/pipermail/r-help/2005-November/082164.html — Saksham, Sep 08 '15 at 12:33
can you give more insight on what would be the input data and in what format do you need the output — Saksham, Sep 08 '15 at 12:35

score 0 · Answer 1 · answered Sep 08 '15 at 13:09

0

Here is a self-made function that solves x^2=n mod m:

f <- function(n,m){which(((0:(m-1))^2 %% m)==(n %% m))[1] - 1}

.

> f(4,3)
[1] 1
> sapply(-10:10,f,5)
 [1]  0  1 NA NA  2  0  1 NA NA  2  0  1 NA NA  2  0  1 NA NA  2  0
>

answered Sep 08 '15 at 13:09

mra68

2,960
1
10
17

Solving quadratic congruence

1 Answers1