Math Help

Archive for January, 2011

Question: Are there any free (or very cheap) SAT prep websites?

I’m re-taking the SAT in May because my math scores were very low (430 in fact) and I desperately need help (need a 500 to get into my desired college). Considering I’m too busy and have no time for a human tutor, does anyone know of a good online service?

Answer: Here is one.

http://38.118.81.253/(X(1)S(b3l4qvmlhbjzrp55w2a3y0i0))/Default.aspx?AspxAutoDetectCookieSupport=1

College Algebra Help – YourTeacher.com – 1000+ Online Math Lessons

Question: Math Help, domain and range.. all real numbers??? CONFUSED.. PLEASE HELP!!!?

in math we are doing functions/function notation and i was just wondering how do you know when to put “all real numbers” for domain and range??

please help, this is urgent!!!!!

Answer: Do it wherever it makes sense. For example:

f(x) = x + 1

has a (largest possible) domain of all real numbers, since you can plug any value of x in and get a valid result for f(x). It’s range will also be all real numbers, since you can get every real number by plugging a value in for x. Another example:

g(x) = 1 / sqrt(x – 1)

This does not have a domain of all real numbers. Think about x = 0. That would leave a square root of a negative number. Think about x = 1. The square root of 0 is valid, but it would leave a division by 0. This function has a (largest possible) domain of x > 1, since every value of x > 1 can be plugged in, and you’ll get a real number back.

As for the range, you know that g(x) > 0 for all x, since sqrt() of anything will return a positive value. Other than that, the range will be all other numbers (this is a little bit more difficult to prove).

Things to look for:

- division by 0 is never defined
- square roots, fourth roots, sixth roots, etc take and return non-negative (i.e. x>=0)
- any logarithms take strictly positive values (i.e. x > 0)

Math Functions & Techniques : How to Find the Domain & Range of a Function

Question: Does anyone know any good sites where i can become an online math tutor?

I tutor math as a second income..its pretty good, but it would be a whole lot better if i can do it online. Anybody know any good sites..thank you for any help you can give.
hmm interesting thanks Crystal

Answer: Try these links. Look through them to see if they’re what you’re looking for.

http://studentoffortune.com/

http://messages.yahoo.com/Schools_&_Education/Homework_Help/Math/threadview?m=tm&bn=1609657496&tid=230&mid=439&tof=5&frt=2

http://www.ehow.com/how_5038224_become-math-tutor-online.html

http://mathonlinetutoring.blogspot.com/

Math Help : Becoming an Online Math Tutor