ln(x+3)
Find the domain.

Question

ln(x+3)
Find the domain.

anonymous · Answer

I thought it was (-3,inf) because the domain must be greater than zero, right?

anonymous · Answer

Yes
$$(-3nf)$$

anonymous · Answer

but this is wrong

anonymous · Answer

If it isn't (-3,inf) what is it and why?

anonymous · Answer

it is

jim_thompson5910 · Answer

The answer is (-3, inf) but maybe they want you to use something else for "inf" (like the actual infinity symbol)

or maybe they want the answer in set-builder notation

anonymous · Answer

Well I am using WebAssign and I've used the infinity symbol. It still isn't working? :(

anonymous · Answer

on line course i bet,  so there is probably some syntax error

anonymous · Answer

can you post the exact question? i have some familiarity with WebAssign

anonymous · Answer

attachment

jim_thompson5910 · Answer

oh it looks like ln(x) + 3

jim_thompson5910 · Answer

so that would make the domain to be (0, inf)

anonymous · Answer

aaah i see the problem

anonymous · Answer

oops! That was my error, sorry

anonymous · Answer

$\ln(x)+3$ is what it means not $\ln(x+3)$

jim_thompson5910 · Answer

that's fine, I've seen plenty of cases where the system will write out ln x + 3 and actually mean ln(x+3) which is very confusing and frustrating

anonymous · Answer

While we are at it, how could I find the X-intercept on this graph? Clearly it doesn't start from the origin

jim_thompson5910 · Answer

y = ln(x) + 3

0 = ln(x) + 3 ... plug in y = 0

solve for x

anonymous · Answer

because webassing is hypocritical
it makes you write "sin(x)" but will itself write lnx

anonymous · Answer

lol, thanks guys! :)