Question

What is the domain of f(x)=log(x)+7?

Answer 1

@jim_thompson5910

Answer 2

Can you plug in x = 0 and evaluate the right side?

Answer 3

and get some number as a result?

Answer 4

If I put f(0)=log(0)+7 wouldn't I get 7?

Answer 5

no, what is log(0)?

Answer 6

In other words, if y = log(x), then 10^y = x

So if x = 0, then 10^y = 0

Can the left side ever be zero?

Answer 7

No, I dont believe so

Answer 8

My guess was x>7 =)

Answer 9

sry page took a bit long to load

Answer 10

you're right, 10^y will NEVER be zero, so log(0) is undefined

Answer 11

Awesome! Thank you!

Answer 12

So this means that x must be positive, which means that the domain of log(x) is x > 0

Answer 13

So the domain of f(x) = log(x)+7 is also x > 0

Answer 14

Oh sry, didn't see your message above about "x > 7", it's not x > 7 it's actually x > 0

Answer 15

No problem at all, I now understand what I did wrong =)

Answer 16

alright great