Cez005
Hi Mike, I determined f(1/x) as (1/x)-x and then worked through the functions in answer choices, landing at B. Do you see any pitfalls to this approach?
Dear
Cez005,
I'm happy to respond.
You ask if there were any pitfalls. No and yes. I am sure your algebra was superb. The drawback is on a larger scale.
To discuss this, I will introduce the following distinction.
Left brain thinking = rule-based; good at step-by-step recipes and procedures; operates with logic and analysis; proceeds step-by-step
Right brain thinking = pattern-based; good at seeing complex connections and larger patterns; operates with analogy and association; proceeds by non-linear leaps
You can read more on this blog:
How to do GMAT Math FasterYou see, left-brain thinkers love to algebra, and they look for any opportunity to use algebra in a step-by-step solution. Even if all the algebra is flawless, the problem with this approach is that it often takes too long. In fact, the GMAT Quant, on higher level questions, loves to create question that are complete traps for someone who opts for the straightforward algebraic solution. This GMAT Prep problem is along these lines.
When I looked at the problem, I solved it in my head in under 10 seconds by observing the patterns. I tried to make this clear in my explanation.
I don't know you, so I don't know whether you are predominately a left-brain thinker. I will say the solution method you described was an extreme left-brain lengthy solution for a problem that can be completed quite quickly with a right-brain approach.
This is the paradox of growth. You are not really preparing for the GMAT if you keep doing the things that already come naturally to you. You improve by stretching yourself to get at least a little better in the areas that are completely unfamiliar.
Does all this make sense?
Mike