arorni
mtambiev
arorni
Can you please explain, how we have come to the required range?
This is exactly what she did
I think you have to specify your question a bit. Which part did you not understand?
I saw Payal's other post on wavy line
https://gmatclub.com/forum/wavy-line-me ... 24319.html. It indeed cleared my doubt about this question, but I am a little confused about drawing wavy lines. Do we always have to start drawing the wavy line from the -ve region (ie Is it the upper right corner)? How the wavy line of (x-1)^2 will look, I got the idea that for even powers the line will remain in the same region but why we have started drawing from the -ve region?
Ok i got you. As you can see in her approach, the largest zero point for x is 5 (from all the others:-3,-2,2,3,5). So its easy to check if the equation gives a positive or negative result, if you plug in numbers that are less than the smallest zero point (here: -3) or greater the largest zero point (5).
So let's try all number greater the largest zero point, which is 5. For example, plug in \(x=10\). Then all terms in the brackets will be positive, so for all \(x>5\) the equation is \(>0\).
Remember:
\(+*+=+\)
\(-*+=-\)
\(-*-=+\)
Further on, for even powers, the line will not cross the axis, but bounces back, for odd powers it does cross the axis.