Question

f(x)=1/sqrt(10x+12)

find the domain

Answer 1

Same thing as before. You cannot take the square root of a negative number.

Answer 2

FURTHERMORE, the result of the square root can't be 0.

Answer 3

So essentially, what's under the square root can't be 0 either.

Answer 4

x>=-1.2

Answer 5

[-1.2,inf)?

Answer 6

Almost! Remember, the denominator can't be 0. This means we can NOT use sqrt(0). So we must discard the "and equal to" part of the inequality. It must be strictly greater than 1.2.

Answer 7

x>1.2? [1.2,inf)

Answer 8

You just entered the exact same interval as last time.

Answer 9

(1.2, inf)

Answer 10

huh? im confused now

Answer 11

Yes x > 1.2. But then you typed in the exact same interval that you did before. ( ) means "does NOT include" so (1.2, inf) means, from 1.2 to infinity and DOES NOT include 1.2

Answer 12

so.. [1.2,inf]?

Answer 13

Oh my. :/

No, You DO NOT want 1.2. Therefore, the left bound MUST be ( not [

Answer 14

LOL... my gosh.. im so lost so would it be (1.2,inf]?

Answer 15

No, you can't include infinity, because you never get there.

Answer 16

But (1.2,inf) isn't correct?

Answer 17

(1.2, inf) should be correct.

Answer 18

It says its incorrect lol! That's why I'm confused.

Answer 19

Oh, sorry, no we're forgetting one VERY simple thing. Its -1.2 ;)

Answer 20

(-1.2, inf)

Answer 21

hahaha yeah I just inputted that. Thanks for the help :)

Answer 22

No problem.