Originally Posted by

**mark** hi, i've got the question

by completing the square, solve the following quadratic equation, giving your answer in surd form

$\displaystyle x^2 - x - 1 = 0$

my answer was $\displaystyle x = 0.5 \pm \sqrt (0.75)$

but the books answer is $\displaystyle x = 0.5 \pm \sqrt (5) frac(2)$

could someone please show me a step by step way of coming to this answer

thanks

ps that last bit was supposed to be the square root sign with the 5 to the right of it, then a division bar beneath them and a 2 underneath that, if someone could tell me how to write that properly that would be appreciated too