Simplifying a rational expression

In summary, the conversation discussed simplifying the expression ##\displaystyle-\frac{1}{(x-2)(x-2)(x-3)}~\cdot~\sqrt{\frac{(x-2)^{2}}{(x-3)(x-1)}}## and specifically addressed the possibility of cancelling the ##(x-2)## term in the denominator with the square root term. It was cautioned that, due to signs, the square root of ##x^2## is not always equal to ##x##. It was also noted that this expression is not a rational function, and the importance of considering absolute value was mentioned.
  • #1
Mr Davis 97
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Given that we have the expression ##\displaystyle-\frac{1}{(x-2)(x-2)(x-3)}~\cdot~\sqrt{\frac{(x-2)^{2}}{(x-3)(x-1)}} ##, how do we simplify it, step by step? Specifically, I am concerned about the ##\sqrt{(x-2)^{2}}## term. Are we allowed to cancel this with the ##(x-2)## in the denominator?
 
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  • #2
Yes.
 
  • #3
paisiello2 said:
Yes.
I disagree. You have to be careful about signs. The square root of x squared is not always equal to x.

Take, for instance, x=0 and evaluate the given expression before and after cancellation. Do the two give the same result?
 
  • #4
jbriggs444 said:
I disagree. You have to be careful about signs. The square root of x squared is not always equal to x.

Take, for instance, x=0 and evaluate the given expression before and after cancellation. Do the two give the same result?
I agree with jbriggs444 here, and would add that ##\sqrt{x^2} = |x|##, which is something I mentioned in your other thread on rational expressions.
 
  • #5
By the way- this is not a "rational function"!
 

FAQ: Simplifying a rational expression

What is a rational expression?

A rational expression is a fraction where the numerator and denominator are both polynomials (expressions with variables and constants).

What does it mean to simplify a rational expression?

Simplifying a rational expression means reducing it to its simplest form by canceling out common factors in the numerator and denominator.

How do you simplify a rational expression?

To simplify a rational expression, factor the numerator and denominator completely and then cancel out any common factors. Then, rewrite the expression using the remaining factors.

What are some common mistakes when simplifying rational expressions?

Common mistakes when simplifying rational expressions include forgetting to factor completely, canceling out the wrong factors, and making mistakes while combining fractions.

Why is it important to simplify rational expressions?

Simplifying rational expressions can help make them easier to work with and understand. It can also help identify any restrictions on the variables and make it easier to solve equations involving rational expressions.

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