Linker can't find mathgl library - c++

Question

I try to make mathgl work, but the linker can't find the library. I installed it through the user repository from arch linux.
I just copied the example program:
#include <mgl2/mgl.h>
int main()
{
mglGraph gr;
gr.FPlot("sin(pi*x)");
gr.WriteFrame("test.png");
}
The official website states you need to link lmgl, but I get this error:
$ g++ main.cpp -lmgl
/usr/bin/ld: cannot find -lmgl
collect2: error: ld returned 1 exit status
I couldn't figure out where to start looking for the library. How can I see where it was installed?
I was looking for libmgl with ldconfig -p getting these results:
$ ldconfig -p | grep libmgl
libmgl2.so.7.5.0 (libc6,x86-64) => /usr/lib/libmgl2.so.7.5.0
libmgl2.so (libc6,x86-64) => /usr/lib/libmgl2.so
libmgl2-qt5.so.7.5.0 (libc6,x86-64) => /usr/lib/libmgl2-qt5.so.7.5.0
libmgl2-qt5.so (libc6,x86-64) => /usr/lib/libmgl2-qt5.so
libmgl2-qt.so.7.5.0 (libc6,x86-64) => /usr/lib/libmgl2-qt.so.7.5.0
libmgl2-qt.so (libc6,x86-64) => /usr/lib/libmgl2-qt.so
libmgl2-glut.so.7.5.0 (libc6,x86-64) => /usr/lib/libmgl2-glut.so.7.5.0
libmgl2-glut.so (libc6,x86-64) => /usr/lib/libmgl2-glut.so

Answer 1

As Amadeus indicated, using
$ g++ main.cpp -lmgl2
should work.