Questions about the world of GRE Math from other sources and general math related questions.
baily106
Course Students
 
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Square Root Question

by baily106 Sat Jul 26, 2014 11:45 am

Hello,

I am referring to question #4 on page 161 of Book 4 (Number Properties). The question asks to simplify the square root of (X raised to the 2 plus X raised to the 2 times 3). I read the explanation. My question is this: in square root cases, do you always keep the expression together when it is subtraction or addition, but are able to separate the square roots when it is multiplication or division?

Thanks.
tommywallach
Manhattan Prep Staff
 
Posts: 1917
Joined: Thu Mar 31, 2011 11:18 am
 

Re: Square Root Question

by tommywallach Fri Aug 01, 2014 10:29 pm

Hey Baily,

Yes. The rule for square roots is:

sq rt. (x * y) = sq rt. (x) * sq rt. (y)

BUT

sq rt. (x + y) DOES NOT EQUAL sq rt. (x) + sq rt. (y)

-t
baily106
Course Students
 
Posts: 49
Joined: Sat May 03, 2014 1:13 am
 

Re: Square Root Question

by baily106 Sun Aug 03, 2014 11:02 am

Got it; thank you!
tommywallach
Manhattan Prep Staff
 
Posts: 1917
Joined: Thu Mar 31, 2011 11:18 am
 

Re: Square Root Question

by tommywallach Wed Aug 06, 2014 9:27 pm

You are welcome, sir!