Question

Find the product of -7-i and its complex conjugate

Answer 1

50

Explanation:

`-7-i\\\\\text{complex conjugate:}\ -7+i\\\\(-7-i)(-7+i)\qquad\text{use}\ (a+b)(a-b)=a^2-b^2\\\\=(-7)^2-(i)^2\qquad\ i=√(-1)\to i^2=-1\\\\=49-(-1)\\\\=49+1\\\\=50`