## anonymous 5 years ago summation notation

1. anonymous

$10+\sum_{1}^{5}(n^3-1)$

2. anonymous

It means: (1^3 -1) + (2^3 - 1) + (3^3 -1) + (4^3 -1) + (4^3 -1) +10

3. anonymous

0 + 7 + 26 + 63 + (oops that last one should be 5^3 - 1) 124 + 10 =230

4. anonymous

i knew it was like that i just wanted to make sure thank you very much!! :-)

5. anonymous

i have another question what is the domain and range of a function?

6. anonymous

sure

7. anonymous

domain is defined by the numbers above and below the summation symbol the range....hmmm I'm not sure on that since the result is one answer not like a function which would have a well...range of answers. Sorry not sure on the theory on that.

8. anonymous

If you are asking about functions in general: domain is asking what numbers can 'legally' be entered for the x value. f(x)=2+x it is ok to put any number in for x so the domain would be all real numbers noted as R or (-oo, +oo) if you like intervals. You only need to worry about domain problems when there are restrictions on valid numbers in the function. For example: NO DIVIDING BY ZERO So the domain for f(x)=1/x ...x can't = 0 ya? So all real numbers != (not equal) to 0. Other rules: can't get square roots of numbers less than 0. Range is just asking what valid answers will pop out of the function.

9. anonymous

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