1. the magnitude, it’s also called its length, or its absolute value
2. you need the difference of the complex numbers
3+4i-(-5+2i) =3+4i+5-2i=8+2i
To find modulus of a complex number z=a+bi we use formula:
|z|=sqrt(a^2+b^2)
you have a=8 and b=2
|z|=sqrt(8^2+2^2)=sqrt(68)=2sqrt(17)
