Question

I give medals!! Determine the values of the variable for which the expression is defined as a real number. (Enter your answer using interval notation.) (1/x2 − 4x − 21)^1/2

Answer 1

set x^2 - 4x - 21 > 0

Answer 2

Mmkay @sourwing

Answer 3

got (x-7)(x+3)>0

Answer 4

-3, 7

Answer 5

I put that I do not know how to put it into interval notation it's confusing/

Answer 6

ok well > sign and < sign open circle I think it's parenthesis

Answer 7

(-3,7)

Answer 8

I put that and it was incorrect

Answer 9

or that could be (-3,0)U(0,7)U(7, oo) kind of forgot

Answer 10

Put that too :/

Answer 11

hmmmmm......
(-00,-3)U (-3,7)U(7,oo)

Answer 12

{x: -3<x<7}

Answer 13

that's set notation... the problem is asking for interval notation