Question 176614
I can write
{{{(x - (4+i))(x - (4-i)) = 0}}}
This equation is true if either {{{x = 4 + i}}}
or {{{x = 4 - i}}}
The function y(x) is
{{{y = (x - (4+i))(x - (4-i))}}}
{{{y = x^2 -(4+i)x - (4-i)x + (4+i)(4-i)}}}
{{{y = x^2 - 4x - ix - 4x + ix + 16 + 1}}} note that {{{i^2 = -1}}}
{{{y = x^2 - 8x + 17}}}
check:
{{{0 = (4-i)^2 - 8*(4-i) + 17}}}
{{{0 = 16 - 8i - 1 - 32 + 8i + 17}}}
{{{0 = 0}}}
OK