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answer of square root 4 must be plus minus 2

 Jun 6, 2014

Best Answer 

 #2
avatar+109812 
+5

ACTUALLY

1) If the square root is written into the question then, by convention, the answer is POSITIVE.

$$\sqrt{4}=+2$$

 

2) However, if the question is

$$x^2=4$$

then this is how you solve it

$$\sqrt{x^2}=\pm\sqrt{4}\\

x=\:\pm\; 2$$

This is because the square root was not a part of the question.  It was introduced as a part of the solution.

So this time there are 2 answers, +2 and -2

 Jun 7, 2014
 #1
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0

Yes, you're right.

 Jun 6, 2014
 #2
avatar+109812 
+5
Best Answer

ACTUALLY

1) If the square root is written into the question then, by convention, the answer is POSITIVE.

$$\sqrt{4}=+2$$

 

2) However, if the question is

$$x^2=4$$

then this is how you solve it

$$\sqrt{x^2}=\pm\sqrt{4}\\

x=\:\pm\; 2$$

This is because the square root was not a part of the question.  It was introduced as a part of the solution.

So this time there are 2 answers, +2 and -2

Melody Jun 7, 2014

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