Math problem help me out!?

Question

Equation:

2x-1/ x^2+3x-1 what is the domain or restrictions? help?

Answer 1

if the problem is (2X-1)/(X^2 + 3X -1) then u need to know that the bottom part can't equal zero. That's ur restriction.

So set the bottom part equal to zero:
x^2 + 3X - 1 = 0

then use the quadratic equation since this is not factorable by mental math unless u r a genius. the 2 roots or restrictions are 0.30278 and -3.3028 so ur domain should be X cannot = 0.30278 and -3.3028.

next time use parenthesis because they do make a difference.

Answer 2

It's not really an equation since it doesn't have an = in it. ☺
OTOH it --is-- a function and one of the places that you have to look at for domain restrictions with functions are denominators of fractions. In this case you have (I think)
(2x-1)/(x²+3x-1) so you need to find any x values that make
x²+3x-1 = 0 (This -is- an equation. A quadratic, in fact ☺)
Solve it (use the quadratic formula, it doesn't factor nicely at all) and you will have 2 values for x at which the denominator vanishes (goes to zero). So the domain of the independent variable x is the set of all real numbers --except-- the two roots you found for the quadratic denominator.

Kewl??

Doug