Identifying the type of expression

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The discussion revolves around identifying types of mathematical expressions, specifically focusing on the simplification of two given expressions. The first expression simplifies to a fractional form, while the second results in a quadratic expression, leading to a debate on terminology regarding their classification. Participants note that constant and square terms can cancel in the second expression, indicating a subjective approach to simplification. A follow-up question introduces additional expressions, prompting further inquiry into whether they are considered fractional. The conversation highlights the nuances in classifying mathematical expressions based on their simplified forms.
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TL;DR Summary: ##(1+ \frac1x)^2 - (1-\frac1x)^2##
##(z+2)^2 -5(z+2)##

Upon simplifying the first I get ##\frac4x##. So isn’t the first expression fractional?
Upon simplifying the second I get a Quadratic expression.
 
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1. If you want to call it that, yes. One could also say that constant and square terms cancel.
2. I get a product -- matter of taste which is simpler

##\ ##
 
Thanks man :)
 
What about ##(x^2+3)^{-\frac13} + \frac23 x^2(x^2+3)^{-\frac43}## ? Fractional expression?
or this ##(x^2+3)^{-\frac13} + 2 x^2(x^2+3)^{-\frac43}## ?
 
The working out suggests first equating ## \sqrt{i} = x + iy ## and suggests that squaring and equating real and imaginary parts of both sides results in ## \sqrt{i} = \pm (1+i)/ \sqrt{2} ## Squaring both sides results in: $$ i = (x + iy)^2 $$ $$ i = x^2 + 2ixy -y^2 $$ equating real parts gives $$ x^2 - y^2 = 0 $$ $$ (x+y)(x-y) = 0 $$ $$ x = \pm y $$ equating imaginary parts gives: $$ i = 2ixy $$ $$ 2xy = 1 $$ I'm not really sure how to proceed from here.

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