OpenStudy (anonymous):

is there a step by step solution to help find the range and domain of a function besides graphing in the calculator? f(x)= x^3-9x+6

7 years ago
OpenStudy (anonymous):

the domain is easy: you just have to check for which values of x the function has no meaning. So for example denominator cannot be 0 or under square root you cannot have negative.

7 years ago
OpenStudy (anonymous):

For the range you need to check the function. x^3-9x+6 the dominant part of a polynomial is always the highest power, so x^3 here

7 years ago
OpenStudy (anonymous):

Do you know how does this function look like? f(x)=x^3

7 years ago
OpenStudy (anonymous):

yes

7 years ago
OpenStudy (anonymous):

OK. So this function will be nearly like that, and x^3 goes from - infinity to +infinity, so this function also will do the same.

7 years ago
OpenStudy (anonymous):

ok thanks. How do yu know when to use brackets [] or commas()?

7 years ago
OpenStudy (anonymous):

for domain and range?

7 years ago
OpenStudy (anonymous):

yes

7 years ago
OpenStudy (anonymous):

[a,b] means all the numbers between a and b including a and b (a,b) means all the numbers between a and b excluding a and b

7 years ago
OpenStudy (anonymous):

and for infinity we always use commas

7 years ago
OpenStudy (anonymous):

ok thanks so much!

7 years ago