MHB Evaluate Fraction: Simplify $\frac {x^2 + 1 - 1}{x^2 + 1}$

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The expression $\frac{x^2 + 1 - 1}{x^2 + 1}$ can be simplified to $1 - \frac{1}{x^2 + 1}$. This simplification is achieved by separating the terms in the numerator, allowing the expression to be rewritten as $\frac{x^2 + 1}{x^2 + 1} - \frac{1}{x^2 + 1}$. The first part simplifies to 1, leading to the final result. Understanding this method of manipulating rational expressions clarifies the reasoning behind the simplification. The discussion highlights the importance of recognizing how to break down fractions to simplify them effectively.
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I have this expression:

$\frac {x^2 + 1 - 1}{x^2 + 1}$

Is there a way to simplify this expression and get:

$1 - \frac {1}{x^2 + 1}$

My professor wrote it on the board and I didn't follow the reasoning.
 
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Re: Evaluating a fracion

Yes, with rational expressions, we may write:

$$\frac{a+b}{c}=\frac{a}{c}+\frac{b}{c}$$

And so what your professor did can be reasoned as follows:

$$\frac{x^2+1-1}{x^2+1}=\frac{x^2+1}{x^2+1}-\frac{1}{x^2+1}=1-\frac{1}{x^2+1}$$

Does that make sense?
 
Re: Evaluating a fracion

MarkFL said:
Yes, with rational expressions, we may write:

$$\frac{a+b}{c}=\frac{a}{c}+\frac{b}{c}$$

And so what your professor did can be reasoned as follows:

$$\frac{x^2+1-1}{x^2+1}=\frac{x^2+1}{x^2+1}-\frac{1}{x^2+1}=1-\frac{1}{x^2+1}$$

Does that make sense?

Ah I see now, thank you
 
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