Find the roots of the following quadratic equation by method of completing the square>

Asked by rahulbharti | 2nd Jun, 2009, 11:22: PM

Expert Answer:

2x² + x - 4 = 0

Multiplying the equation by 2 through out.

⇒ (2x)2 + 2x  - 8 = 0

⇒ (2x)2 + 2 x (2x) x 1/2+ (1/2)- (1/2)2  - 8 = 0

⇒ (2x + 1/2)2 - 33/4 = 0

⇒ (2x+ 1/2) =  33/4

⇒ 2x =  33/4 - 1/2

⇒ x = (( 33/4 - 1)/2)

  x = (33 - 1)/4  and -(33 + 1)/4

 

 

 

Answered by  | 3rd Jun, 2009, 09:39: AM

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