Login

Welcome, Guest. Please login or register.

March 29, 2024, 10:12:06 am

Author Topic: Could someone please tell me where I went wrong?  (Read 531 times)  Share 

0 Members and 1 Guest are viewing this topic.

Rose34

  • Trendsetter
  • **
  • Posts: 158
  • Respect: +2
Could someone please tell me where I went wrong?
« on: March 11, 2020, 10:20:03 pm »
0
How to complete the square?
y=2x^2 -4x+6

My working out:
y=2(x^2 -2x+3)
y=2(x^2-2x+1+3-1)
y=2(x-1)^2+2

But the answer in the book in:
y=2(x-1)^2+4

Thanks in advance!

lm21074

  • MOTM: JAN 19
  • Victorian Moderator
  • Forum Leader
  • *****
  • Posts: 589
  • Respect: +594
Re: Could someone please tell me where I went wrong?
« Reply #1 on: March 11, 2020, 10:49:58 pm »
+3
Hi Rose!

I think that the second step should be written as:


As we have taken out a common factor, all the terms have to be multiplied by two. It's like taking out a common factor of an expression such as: All terms inside the brackets need to be multiplied by the term on the outside.


Great question btw!
Good luck for your upcoming methods SAC :)
2021: VCE
2022: Science / Arts @ Monash

Rose34

  • Trendsetter
  • **
  • Posts: 158
  • Respect: +2
Re: Could someone please tell me where I went wrong?
« Reply #2 on: March 11, 2020, 11:11:47 pm »
+1
Hi Rose!

I think that the second step should be written as:


As we have taken out a common factor, all the terms have to be multiplied by two. It's like taking out a common factor of an expression such as: All terms inside the brackets need to be multiplied by the term on the outside.


Great question btw!
Good luck for your upcoming methods SAC :)

Thanks!