Answers

2014-09-13T16:44:23+08:00
4x² + 1................................
( 2x - 
√-1) (2x +√-1) .........................
( 2x - i ) ( 2x + i )...................
i refers to an imaginary number,we used it when cases like √-1 occur... so the factors are "( 2x - i ) and ( 2x + i )" or "[ x+(1/2) i ] and [ x - (1/2) i]".... 
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