Question

Find a polynomial function p of lowest​ degree, having rational​ coefficients, with the given zero. 5i

Answer 1

If we have one zero of +5i, we also have to have its conjugate which is -5i. Therefore, the factors that we will FOIL to get that polynomial are (x+5i)(x-5i). That distribution results in
`x^(2) -25 i^(2)`. I'm sure by now you know that i squared is equal to -1, so -25(-1) = 25. So our polynomial is
`x^(2) +25=y`