If #x is defined for all x 2 as the square root of the number that

Question

If #x is defined for all x > –2 as the square root of the number that is 2 more than x, what is the value of #7 - #(-1) ?

A. 0
B. 1
C. 2
D. 3
E. 4

RiyadhArifin237 · Answer

Is it really math from sequence and funtion topic??

Posted from my mobile device

wadhwakaran · Answer

#x= sqrt(x+2)
#7= sqrt(9)=3
#-1= sqrt(-1+2)=1
3-1=2

RiyadhArifin237 · Answer

Correct is 4.. we need some official solution from GMAT Club..

Posted from my mobile device

Nefertiti9 · Answer

IMO 2
#x is defined for all x > –2 as the square root of the number that is 2 more than x
This essentially means 
 #x=\sqrt{(x+2)} 
Few examples would be :
 #3 = \sqrt{(3+2)}  and  #4 =\sqrt{(6)} 
now we need to find #7 and #1
 #7=\sqrt{(7+2)} = \sqrt{ 9} = 3
#-1=\sqrt{(-1+2)} = \sqrt{1 }= 1
 
so, #7-#1= 3-1 =2

BrushMyQuant · Answer

Given that #x is defined as the square root of the number that is 2 more than x and we need to find the value of #7 - #(-1)

#7 = square root of the number that is 2 more than 7
=> #7 =  \sqrt{(7 + 2)}  =  \sqrt{9}  = 3
Similarly, #(-1) =  \sqrt{(-1 + 2)}  =  \sqrt{1}  = 1

=> #7 - #(-1) = 3 - 1 = 2

So,  Answer will be C 
Hope it helps!

Watch the following video to learn the Basics of Functions and Custom Characters

https://www.youtube.com/watch?v=b7JoMX0gk8M

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

If #x is defined for all x > 2 as the square root of the number that

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Problem Solving (PS) Questions