completing the square, does the book have it wrong?
complete square 2x^2 - 12x + 6
the book got
2(x-4)^2 - 29
but i got
2(x-4)^2 - 26
As -4^2 = 16 x 2 = 32, 6-32 = -26?
Did i do something wrong? the book has it as 3-32 = -29
the book got
2(x-4)^2 - 29
but i got
2(x-4)^2 - 26
As -4^2 = 16 x 2 = 32, 6-32 = -26?
Did i do something wrong? the book has it as 3-32 = -29
my bad original equation was
2x^2 - 16x + 6
2x^2 - 16x + 6
Original post by TimetoSucceed
my bad original equation was
2x^2 - 16x + 6
2x^2 - 16x + 6
In that case you're right, the book is wrong.
2x^2 - 16x + 6
2(x^2 - 8x + 3)
2((x-4)^2 - 16 + 3)
2((x-4)^2 - 13)
2(x-4)^2 - 26
so it's this, you were right
2(x^2 - 8x + 3)
2((x-4)^2 - 16 + 3)
2((x-4)^2 - 13)
2(x-4)^2 - 26
so it's this, you were right
(edited 13 years ago)
Original post by Artemis 97
2x^2 - 16x + 6
2(x^2 - 8x + 3)
2((x-4)^2 - 16 + 3)
2((x-4)^2 - 13)
2(x-4)^2 - 26
so it's this, you were right
2(x^2 - 8x + 3)
2((x-4)^2 - 16 + 3)
2((x-4)^2 - 13)
2(x-4)^2 - 26
so it's this, you were right
Neatly edited, was about to point out the mistake
Original post by EEngWillow
Neatly edited, was about to point out the mistake
lol i just noticed when i posted it and i realised i'd get about 50 people telling me i'd done it wrong instantly :PQuick Reply
Related discussions
- OCR GCSE Maths Paper 6 (Higher)
- Mistake in the Edexcel practice book for Year 1/ AS Maths?
- Volumes of revolution
- SMC Tips and Tricks
- Physics Alevel question :- electromagnetism induction and alternating current
- Maths help
- Help urgent maths
- Bmo 2023/24
- circle question help
- help
- Problem solving the smc 2023
- Maths Core Pure AS Series question
- WJEC chi distribution question
- Finding values of k for two distinct real roots
- 2022 Edexcel Maths GCSE (Higher) Checklist
- Isaac physics A Square Pulse C3 - PLEASE help
- A Level Maths : Common Mistakes/misconceptions
- Mathswatch
- why can't I square both sides of the inequality in the case?
- TSR Goes Green: Do you study outside?
Latest
Trending
Last reply 2 days ago
Did Cambridge maths students find maths and further maths a level very easy?Last reply 2 weeks ago
Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrongMaths
71
Trending
Last reply 2 days ago
Did Cambridge maths students find maths and further maths a level very easy?Last reply 2 weeks ago
Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrongMaths
71
