Methods Exam 1: Discussion!

[speedy]

Yep that's how i did it haha, i just hope +-1/2 (not just +1/2) was an acceptable answer for the second question, cos i don't know if it meant principal square root or just square root (no restrictions?) I drew the hyperbola and pointed to where each gradient would apply.........if i lost that gonna be so pissed haha

The calculator just gives 1/2

Edit: are you saying you don't know if it's +/-root(...)?

[GeniDoi]

 A+ cutoff predictions? Could it go as low as 33-34?

[katiesaliba]

30/40. To get low 30s, is this an okay mark (provided I'm not absolutely massacred in exam 2 tomorrow :O )? 

[BLACKCATT]

I reckon the cutoff for A+ will be around 36

[S61778]

For the conditional prob. question with m,

I accidently changed e^-x/5 to e^-x/2 after I wrote the correct integral statement

So, ended up with 2 - (2/sqrt(e))

How many marks would I lose for this?

[jumcakes]

Yep that's how i did it haha, i just hope +-1/2 (not just +1/2) was an acceptable answer for the second question, cos i don't know if it meant principal square root or just square root (no restrictions?) I drew the hyperbola and pointed to where each gradient would apply.........if i lost that gonna be so pissed haha

We're given the function as f(x)= root(x^2+3), where the bottom half of the hyperbola is -root(x^2+3) so the function f(x) is only the upper branch :/ but depends on what VCAA has to say.

[DanielJ]

Yep that's how i did it haha, i just hope +-1/2 (not just +1/2) was an acceptable answer for the second question, cos i don't know if it meant principal square root or just square root (no restrictions?) I drew the hyperbola and pointed to where each gradient would apply.........if i lost that gonna be so pissed haha

sqrt (.25) does equal +-1/2, however the gradient of that function at x=1 is increasing, meaning you want the positive one only.

[Aman476]

Yeah true, but i still don't know my spec teacher said if there were no range/domain restrictions you can't assume it means positive or negative (unless its like something that varies with time as it can be in two places at once), yeah so logically i'd say +- but everyone i spoke to wrote +1/2 only......haha can't afford to lose it since i already lost that last point (haha didn't realise f(5/2) was greater than f(6) haha)

[Aman476]

sqrt (.25) does equal +-1/2, however the gradient of that function at x=1 is increasing, meaning you want the positive one only.

Yeah look i think you guys are right, it's annoying though, cos if we had to write a square root function anytime they would expect us to explicitly mark the sign, but they didn't in their question so annoying

[Miokovic]

Here are my preliminary solutions guys

I didn't check them, so I may have a few mistakes, but based on conversations with guys who did the exam they seem correct.

P.S. I have a blank copy of the exam too, so I'll upload that next.

your Q10. b. i).
Height isn't v, its v-4?

[GeniDoi]

Would you get any marks if you evaluated the integral between -1 and 3? Rather than from -1 to 2? As well as the area being subtracted from 16 of course.

[jumcakes]

your Q10. b. i).
Height isn't v, its v-4?

Triangle OVU (big triangle) was used, not the small shaded triangle. I think there were multiple ways to do this question.

[Carl09]

For the question where we had to sketch the cubic, did we need to label the intercept at (0,0)?  I figured since the question didn't say to then it doesn't matter, but I'm starting to  get worried about it

[Miokovic]

Triangle OVU (big triangle) was used, not the small shaded triangle. I think there were multiple ways to do this question.

Ahh I see, thank you

[Aman476]

You know i was just thinking, i spoke to a lot of people who were 'leaving exam two from last year till today" i felt so bad for em, because that last question on today's exam 1 was basically just last year's one on exam 2, unlucky!