Question

Using the given zero, find all other zeros of f(x).

-2i is a zero of f(x) = x^4 - 45x^2 - 196

2i, 14i, -14i

2i, 7, -7

2i, 14, -14

2i, 7i, -7i

Answer 1

might want to just plug and chug the options to see what fits

Answer 2

i forgot how to use imaginary numbers, im on a semester review, and this was from near the beginning of the year

Answer 3

u ave 2 subsitute the value -21 in x, then simplfy

Answer 4

the value is 2(i) not 21.

Answer 5

sory my bad, then did u subsitute that in the equation

Answer 6

16i -90i^2 - 196

Answer 7

now what do i do?

Answer 8

since -2i is a given root, its conjugate pair 2i is a root, which is given in all the options.

try x=7 and x=14 to see if they zero it out

Answer 9

or you can run the quadraitic formula if need be