Posted by **kristie** on Monday, July 17, 2006 at 3:22pm.

How do you find the domain of log(x^2-4)?

and how about this one? e^(3x+4)?

Please help me!

Well kristie, you might recognize log(x^2-4) = log((x-2)(x+2)) and then use a property of logs to see it as a sum, i.e., log(ab)=log(a)+log(b). You are then expected to know that the log function is only defined for positve values. Thus you only want x values that make the argument positive.

For the second you want the values that e^y is defined, where y = 3x+4. What values can an exponent be?

thanks, Roger!

I get the first one, but I'm still a little confused about the second one. I thought an exponent could be any values. So would that make (-infinity, _infinity)?

yes, I think you understand it. Exponents can assume any values.

Just beware of a number with a fractional exponent, such as e^(1/(x-1)) for example. Here you need to restrict x not equal 1.

## Answer This Question

## Related Questions

- math - Logarithm!!! Select all of the following that are true statements: (a) ...
- Trigonometry - This is a logs question If u=x/y^2, which expression is ...
- Math Help Please - Which of the following expressions is equal to log (x sqrt-y...
- TRig WIth LoGs help1!! - i have problem i can't solve and the book is no help.. ...
- mathematics -logs - which three statements are true? a) if x= -10^4 then log 10...
- math - write as a single logarithm: -2logbase3(1/x)+(1/3)logbase3(square root of...
- math(Please help) - 1) use the properties of logarithms to simplify the ...
- LOGARITHMS - HI THE QUESTION STATES THAT ONE SHOULD CALCULATE THE LOGS WITHOUT ...
- precalc(LOGS) CONFUSED! - How do I rewrite without logarithms?? 2. log x= log a...
- algebra homework - please check my answers. Solve the logarithmic equation. Be ...

More Related Questions