Algebra

 

Let f(x) = \sqrt{x}    
Find the largest three-digit value of x such that f(x) is an integer.    

 

The largest three-digit integer is 999.    

 

Take the square root of it                         sqrt(999) = 31.607    

 

Drop the fractional part                             31        

 

Square it                                                    31²  =  961     and that's your answer    

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