Year 12s: what will be the first way you research your future options? >>

Completing the square

a)Write the expression x2+bx+c in the form (x+h)2 +k
b) Hence, show that the solution of the equation x2+bx+c =0 is x=-b/2 ± √(b2/4) - c

Reply 1

EricPiphany

Original post by algebrax1

a)Write the expression x2+bx+c in the form (x+h)2 +k
b) Hence, show that the solution of the equation x2+bx+c =0 is x=-b/2 ± √(b2/4) - c

Nice exercise you have there :smile:

Reply 2

B_9710

Do you know how to complete the square at all?

Reply 3

BobBobson

Imagine b and c are numbers and do what you would normally do to complete the square.

Reply 4

RDKGames

Study Forum Helper

Original post by algebrax1

a)Write the expression x2+bx+c in the form (x+h)2 +k
b) Hence, show that the solution of the equation x2+bx+c =0 is x=-b/2 ± √(b2/4) - c

Good luck with that :smile:

Post any working out if you get stuck :smile:

Reply 5

Zacken

Original post by algebrax1

a)Write the expression x2+bx+c in the form (x+h)2 +k
b) Hence, show that the solution of the equation x2+bx+c =0 is x=-b/2 ± √(b2/4) - c

What the above posts are trying to get across is that this isn't a "do-my-homework-for-me" site. We're here to help you learn maths, not mindlessly do your work for you. So please, tell us what you've tried, what you're stuck on, your own thoughts on the problem. We'll nudge you towards the right answer and make it a learning experience. Don't just post the question, that's not only incredibly damaging for your education but also rather rude.

Thanks.

Reply 6

mik1a

Let's give a clue.

Multiply out the right hand equation, and equate the coefficients of x and the coefficients of the remaining terms with no x factor. Now solve for h and k.

Congratulations, you've now completed all the squares.