Question

Find the polynomial function with the degree of 3 and the zeros 4i and 5.

Answer 1

Degree = 3, x= 5, x=4i
(x+1)(x-5)(x-4i)(x+4i)
Not sure if thats correct...

Answer 2

x^2-4x-5

Answer 3

and thats where I get confused

Answer 4

The zeroes are 5 and 4i... if you have 4i you have -4i

y = (x - 5)(x - 4i)(x + 4i)


Don't know where you go the (x + 1) from

Answer 5

y = (x - 5)(x^2 + 16)
y = x^3 - 5x^2 + 16x - 80

Answer 6

ok , so why is it a +16 and not -16
I also get confused on the middle part of the equation is it:
(x-5)(x^2+4xi-4xi-16), and since the 4xi cancel each other other thats why we dont use them?

Answer 7

-4i * 4i = -16i^2 by definition i^2 = -1 so
-16 * -1 = +16

Answer 8

ok, I'll to remember that for the test. Kinda of confusing but I'll get it.