f(x) =square root of x - 1/x + 2

Determine values of x for which

1) f(x)= 0

2) f(x) will be a real number.

Thanks in advance

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- Sep 21st 2013, 09:23 AMBonganiteddrational expressions
f(x) =square root of x - 1/x + 2

Determine values of x for which

1) f(x)= 0

2) f(x) will be a real number.

Thanks in advance - Sep 21st 2013, 09:31 AMPlatoRe: rational expressions
- Sep 21st 2013, 09:48 AMBonganiteddRe: rational expressions
The first one.

- Sep 21st 2013, 09:56 AMPlatoRe: rational expressions
- Sep 21st 2013, 10:19 AMBonganiteddRe: rational expressions
X>=1 nt sure abt the denomenator

- Sep 21st 2013, 10:33 AMHallsofIvyRe: rational expressions
Do you know "if a> b and c is positive then ac> bc. If a> b and c is negative then ac< bc."

If x+ 2 is positive, then multiplying both sides by it gives $\displaystyle x- 1\ge 0$. When is x+ 2 positive?

If x+2 is negative, then multiplying both sides by it gives $\displaystyle x- 1\le 0$. When is x+ 2 negative? - Sep 21st 2013, 12:41 PMvotanRe: rational expressions
- Sep 24th 2013, 10:44 AMBonganiteddRe: rational expressions
Thanks you all who contributed.

I now understand the problem

1) The expression will be equal to zero if we set the radicand numerator = 0

2)f(x) will be real 1) x is nt = -2

X>=1 or x< -2 - Sep 24th 2013, 02:10 PMHallsofIvyRe: rational expressions
Do you now understand that this was NOT a "rational expression"?