Question

what do i do when there is a negative in the front of the sqrt
example
-sqrt72

Answer 1

You are aware of complex numbers???

Answer 2

What topic are you doing??

Answer 3

generally people assume the positive square root (the principal value). But with the minus sign, they want you to use the negative value of the square root.

Answer 4

so how do i do that
and im doing a review packet

Answer 5

You don't do anything.
however, given
\[ - \sqrt{72} \]
I would try to "simplify" it by factoring 72 into primes:
72= 2*36= 2*3*12=2*3*3*4= 2*3*3*2*2
then look for pairs of numbers: 3*3 and 2*2 to "pull out" of the square root.
so
\[ -\sqrt{72}= -\sqrt{3*3*2*2*2} =- 3*2\sqrt{2}= -6\sqrt{2} \]

Answer 6

ohh ok

Answer 7

what if the problem has a plus or minus sign in front of it

Answer 8

\[\pm \sqrt{54}\]

Answer 9

just leave the plus/minus in the final answer.
54= 2*27= 2*3*9= 2*3*3*3
only 1 pair of numbers: 3*3
so
\[\pm 3\sqrt{2*3}= \pm 3\sqrt{6} \]