Q10 MC 2020 Sample HSC (1 Viewer)

[Jord_o]

How is the answer for Q10 of the 2020 HSC Sample paper A? What maths have they done? Can someone please explain?

 

[jimmysmith560]

I believe this may help:

 

[Jord_o]

I believe this may help:

View attachment 31003

Hey, thanks! That all makes perfect sense, but I can't see the flaw in my logic here:

 

[jimmysmith560]

Hey, thanks! That all makes perfect sense, but I can't see the flaw in my logic here:
View attachment 31004

No worries!

My knowledge of this is very limited, so I can't help much beyond this point. Sorry about that

Perhaps someone who's good at maths could comment on your approach.

 

[zizi2003_]

Correct me if I'm wrong - but doesn't the scale factor only apply to the x values of the function? not the constant? Thus it should be only x/2 in your second step.

 

[Jord_o]

Correct me if I'm wrong - but doesn't the scale factor only apply to the x values of the function? not the constant? Thus it should be only x/2 in your second step.

This is true, however (x/2 - 4) does not result in the movement of “4 units to the right”, rather it translates the function 8 units to the right as with a common denominator, the inside function is (x-8)/2.

 

[CM_Tutor]

Horizontal dilation stretches / shrinks relative to the origin. Thus, it will cause the position of all roots (except the one at the origin, if there is one) to move. You are applying a dilation relative to the existing root at , but that's not how a dilation is defined within the syllabus.

 

[5uckerberg]

How is the answer for Q10 of the 2020 HSC Sample paper A? What maths have they done? Can someone please explain? View attachment 31002

How is the answer for Q10 of the 2020 HSC Sample paper A? What maths have they done? Can someone please explain? View attachment 31002