Can anyone explain question 23 on the non-calc higher paper set a?

  • 0 votes
Posted Sun 10th June, 2012 @ 13:06 by Leah

3 Answers

  • 2 votes

As AD bisects BC, DC=BD=1cm

Then draw the two right angled triangles ADC and BDX which are similar triangles

Label DC and BD as 1 and label AC as 2.

Using Pythogras' Theory, (AD)^2=2^2-1^2=3 so AD=sqrt3

Therefore AD: BD = sqrt3 : 1(this is the length scale factor)

DC : XD

sqrt3 : 1 (length scale factor)

1 : ?

To make sqrt3=1 you must divide bysqrt3 and so you do this to both sides to make...

sqrt3/sqrt3 : 1/sqrt3

Hope this helps! :)

Also how did you do the last question on this paper?

Answered Sun 10th June, 2012 @ 13:41 by Dilly
  • 2 votes

That's great, thank you so much! :)

I struggled with the last question too, my maths teacher explained it and got a=50, b=50 and k=4. The answers are different from the mark scheme, but there are a lot of errors in that so we aren't 100% trusting of it.

I vaguely understand some of it, I get how k=4 as because of f(ax), it is compressed horizontally by 1/4. But I don't quite get the rest, hopefully someone else will be able to explain it on here! :) 

Answered Sun 10th June, 2012 @ 14:21 by Leah
  • 0 votes

Thanks anyway!

Answered Sun 10th June, 2012 @ 15:14 by Dilly