Question

How do you solve `2x^2+4x-1=0` by completing the square?

Answer 1

`x=-1±1/2sqrt6`

Explanation:

`2x^2+4x-1=0`

`x^2+2x-1/2=0`

`(x+1)^2-1-1/2=0`

`(x+1)^2=3/2`

`x+1=±1/2sqrt6` (Note that `sqrt(3/2)-=1/2sqrt6`.)

`x=-1±1/2sqrt6`