Questions from VCAA 2006 sample exam 2 CAS

[vea]

Hey there, here are two questions from the sample exam I couldn't figure out, iTute answers were not much help either...

The answer to 12 is D and the answer to 13 is E

Thanks in advanced.

Also, can someone teach me how to attach files with the questions? I try to attach them as bmp and jpeg files but they're too large. :\

[vea]

Ah, I think you're looking at the 2006 NON-CAS trial exams.

The two questions I have here are totally different.

I've resolved Q13 already anyways so someone help me with Q 12 please

[JinXi]

Ah, I think you're looking at the 2006 NON-CAS trial exams.

The two questions I have here are totally different.

I've resolved Q13 already anyways so someone help me with Q 12 please

Yeah realised that and deleted my post =(

[JinXi]

Question 12

F(t)>0 when   t> 0 as if t< 0, the graph would fall below the x-axis. Eg. when you integrate, if the top (t) is smaller than the bottom, you will get a -ve number.

I think thats what the question is trying to ask. And it's undefined if t=0

Edit : the graph is presumably e^x, integrating e^x will give the same, so if you sub say t=-1 ,t=0, e^(-1)-e^(1) = -ve, whereas they're are asking for F(x) >0

Hard to explain T.t

[vea]

Well iTute's answer is:

From graph:

Therefore the answer is...


EDIT: They were right, typo on my behalf :p

[JinXi]

Well iTute's answer is:

From graph:

Therefore the answer is...

I think it meant

Don;t take my word for it though.

[Whatlol]

first of  all if you integrate from a to 0 you will obtain a negative value. i.e having a negative number for your upper terminal will yeild a negative area (only in this scenario as the function is above the x -axis) . This elimates options ,a b  e. Now if you include 0 you end up with an answer of 0. Since we want it greater than 0, you cant include t = 0. Therefore you can only have t as all elements of (0, b]. as the rest yeilds an answer either equal to 0 or below 0.

[vea]

Thanks, appreciate the help.

[Whatlol]

Thanks, appreciate the help.

no probs, any others?