Exam 1 Answers?

[jimbo9]

The answer is B: 2.3 for Q9 of Geometry and Trigonometry. You need to use similar triangles, and use the fact that the area of the triangular face of the smaller wedge is half that of the larger wedge.

That's wrong. The area of the triangular face of the smaller wedge is not half that of the larger wedge. It's actually 1 to 2^(2/3)

This question is nothing to do with areas or similar triangles. It's a similar solids problem.

[Han123]

Actually the volume was half for the smaller wedge (k^3) so you had to cube root that find the length of the smaller wedge then take that away by 8, you get A

This would normally be the case, however not all the 3 dimensions were changed, only the area of the triangle becomes smaller and then length going towards the back stays the same so k^2 must be used instead.

[jimbo9]

Sorry I missed your earlier reply.

[jimbo9]

Apologies to all. I stuffed up. It is B.

Calling the wedge similar is a bit naughty by VCAA though.

[Law]

Can someone explain Matrices Q3?
Why is it not bipartiate graph instead of tree? My friend told me  if it wasnt tree then there would be no Es in the answer sheet 

[StupidProdigy]

Apologies to all. I stuffed up. It is B.

Calling the wedge similar is a bit naughty by VCAA though.

It is similar though, nothing 'naughty' about it. Not having a crack at ya haha 
For those interested scale ratio=((8-d)/8)
area scale ratio=((8-d)/8)^2
((8-d)/8)^2=1/2 gives d is approx 2.34
A was arrived at if you did ((8-d)/8)^3=1/2

[jimbo9]

Normally when they use the word similar they mean geometrically similar with all lengths in the same ratio. They say the wedges are similar but the smaller wedge has the same length so the shapes are not actually similar.

[rbhalla30]

Hey Guys, I'm sure i lost 3 marks, however i had not predicted any study score. Would have any idea what would i get if i lost 3. Im hoping to do well on exam 2.

[schooliskool]

Hey Guys, I'm sure i lost 3 marks, however i had not predicted any study score. Would have any idea what would i get if i lost 3. Im hoping to do well on exam 2.

It depends on your SACS and ranking, but losing 3 marks on the first and getting full on the second is 47-48

[rbhalla30]

It depends on your SACS and ranking, but losing 3 marks on the first and getting full on the second is 47-48

I probably wont get full but out of 60, im likely to get at least 54. My Internal score was 93% and I reckon that my school gives us VCAA level questions. In such situation is 40 a possibility?

[jimbo9]

It is similar though, nothing 'naughty' about it. Not having a crack at ya haha 
For those interested scale ratio=((8-d)/8)
area scale ratio=((8-d)/8)^2
((8-d)/8)^2=1/2 gives d is approx 2.34
A was arrived at if you did ((8-d)/8)^3=1/2

VCAA accepted both A and B as correct.

[Peanut Butter]

VCAA accepted both A and B as correct.

How do you know?

[jimbo9]

How do you know?

Straight from the VCAA co-ordinator. It was the right thing to do IMO.

[keltingmeith]

Straight from the VCAA co-ordinator. It was the right thing to do IMO.

Ehhh, I reckon it's a cop out tbh. I'm curious as to who this VCAA coordinator is, I didn't think VCAA would have an overarching person in charge of everything like this.

[jimbo9]

Ehhh, I reckon it's a cop out tbh. I'm curious as to who this VCAA coordinator is, I didn't think VCAA would have an overarching person in charge of everything like this.

Sorry - should have said it was the VCE coordinator at our school. I think VCAA also had the same situation with a question in Specialist. Errors is exam papers will happen - they are written by humans!