Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Your explanation helped.. The reasoning behind putting the absolute symbol || is to get a positive number always. There can be mutiple values for x.. But |x-1| will always be positive..

Your explanation helped.. The reasoning behind putting the absolute symbol || is to get a positive number always. There can be mutiple values for x.. But |x-1| will always be positive..

Another approach in order to avoid a deep undertsanding of what are the tricks behind sqrt(x) and x^2 functions ... Finally not a so good idea?

In short :
o sqrt(x) = 1 => x = 1 as a the square root function is only definied for x >=0.
o x^2 = 1 => x=-1 or x=1 as the square function is definied for all x and is symetrical to the Y-axis ((-x)^2 = (-1)*(x)^2 = 1 * (x)^2 = x^2).