what is the square root of 121

Question

 i need help with this question because i am really dumb

Answer 1

The square root off 121 is eleven. PERIOD.  Not -11.

 

You're not dumb, but it is time to memorize quite a few of the perfect squares, i.e. numbers whose square roots are positive integers--because these figure in a lot of mathematics applications.

 

In a pinch, you can always use a calculator to find the square root of any positive integer; if the result is another integer, then you were dealing with a perfect square--otherwise the non-integer square root of an integer is just an approximate decimal value for an IRRATIONAL number.

 

Examples: Square roots of 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 17, etc. are irrational (not integers because this list contains NO perfect square integers).

 

Note The solutions to x² = 121 are ±11 BUT THIS DOES NOT MEAN THAT THE SQUARE ROOT OF121 IS -11.

Answer 2

sqrt( 121 ) 

sqrt( 11 * 11 )

sqrt( 11^2 ) 

+/- 11 <------ because (+11) * (+11) = 121 OR (-11) * (-11) = 121 

 

Examples: 

sqrt( 25 )
sqrt( 5 * 5 )
sqrt( 5^2 )
+/- 5 <------ because (+5) * (+5) = 25 OR (-5) * (-5) = 25

 

sqrt( 4 )
sqrt( 2 * 2 )
sqrt( 2^2 )
+/- 2 <------ because (+2) * (+2) = 4 OR (-2) * (-2) = 4

 

 

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