question (s) regarding E1 and E2?

[gilla]

hey guys,  hope you all did well

i have a few questions:

E1: how many marks lost if we left dy/dx in terms of 'k'?

E2: for the question where it asks for Cartesian form (2d), do they want coordinates or x + yi, and if we left in coordinates, would we loose marks?

E2: for the last question, where we had to use pythag, i let Y1= the integral expression and Y2=1200, then i went to the table Ti 84 has and looked for when Y2 and Y2 were appox the same values. I ended up evaluating it as t ~ 245.5. I did this method becuz i thought it would take way to long to sketch. If i sub in t =245.5, i set get TT's answer of 1296m but would i lose a mark?

[TonyZ]

E2: for the question where it asks for Cartesian form (2d), do they want coordinates or x + yi, and if we left in coordinates, would we loose marks?

check vcaa specialist maths 2008 assessment report, 5c is a similar question to this one.. and it says coordinates or equivalent complex number.

[TonyZ]

just wondering..if i calculated the distance the boat travelled and forgot to calculate the distance between the device and the boat.. how many marks am i going to lose..

[NE2000]

just wondering..if i calculated the distance the boat travelled and forgot to calculate the distance between the device and the boat.. how many marks am i going to lose..

They would probably attach one mark to finding t.

Now it depends on whether they attach the second mark on finding distance boat travels and the third mark on pythagoras which is pretty much answer or whether they attach the second mark on recognizing pythagoras and the third mark on applying the distance boat travels. It's probably impossible to predict.

Just a question. Are they strict on units, particularly for equations where you normally put units in brackets eg. (m/s)? Too often I leave off units where I don't have a numerical answer so yeah...

[TonyZ]

how about if i forgot to calculate the distance that the car and the motorcycle travelled?...

[gilla]

but in 5c it says

Find the points of intersection of the curves given by
z−i =1 and Re (z) = − 1
3Im (z).

Doesn't specify coordinate or cart, but in this yrs exam it said Cartesian

[TonyZ]

i think both are ok...they specify "in cartesian form" because they don't want the answer in polar form as it would be too easy...(2cis pi/6 and 2cis -5pi/6)