find the value that makes this expression undefined?

Question

(y^2-16)/(y^2+16)

Old joke.
And my mom is dead @$$hole.

POSSIBLE ANSWERS:
4
-4
ALL REAL #S
NONE

Answer 1

in order for the expression to be undefined the denominator needs to be 0, as anything over 0 is undefined.

y^2 + 16 =0
y^2 = -16

no real solutions..

for imaginary solutions y needs to be +/- 4*sqrt(-1)

y = +/- 4i

Answer 2

the reply would prefer to be imaginery. you positioned the denominator =0 because you won't be able to divide through 0 it truly is undefined. In doing so, you've y^2+16=0 hence y^2=-16 and so the in trouble-free words a danger solutions will be 4i and -4i

Answer 3

To make it undefined, the bottom has to be zero, so solve
y² + 16 = 0
y² = - 16
y = ±4i.

Can y be a complex number? If only real, the expression will not be undefined.

Answer 4

There can't be a value that will make this expression undefined, because if you plug in any number for the y and square it, you will get a positive number, and add a positive number you will have a positive number again. And you can divide any number by a positive number.

Answer 5

Your choices do not include the correct answer, which is y = ± i4

Answer 6

your mom.