VCE Specialist 3/4 Question Thread!

[martin1106]

thank u

[martin1106]

 For the last step, the answer is

 but why cannot I use the general solution i.e.

 Is that related to the restricted domain of the argument of the complex number ??

 thanks

[Jenny_2108]

For the last step, the answer is

 but why cannot I use the general solution i.e.

 Is that related to the restricted domain of the argument of the complex number ??

 thanks

You can use the general solutions, but it will be because the intervals between solutions in this equation are instead of

In the worked solution, they don't wanna separate solutions so they combine them

[martin1106]

You can use the general solutions, but it will be because the intervals between solutions in this equation are instead of

In the worked solution, they don't wanna separate solutions so they combine them

My worked general solution is the same as urs

so in the real exam can i write like that or I have to combine the two answers together? ennjy

[Jenny_2108]

^ I think it should be fine for both

Like for solving general solutions of sin(x), there is an alternate formula as well
The formula look different but when you substitute values of k or n, the solutions will be the same

[martin1106]

Thanks ennjy

[generalkorn12]

Would anyone be able to explain the following question from NEAP:

I've always just considered using a maxima/minima approach, using the boundary of S as being (x,y) coordinates and just using distance formula, but what they've done is us |u-w|, which I thought would give the distance between the circles centre and w...

[Mr. Study]

Hey,

Question in the diagram.

For where the arrow is pointing, I don't really understand how they can make that statement.

Thanks!

[BubbleWrapMan]

Basically equate with , then you get by equating coefficients.

[martin1106]

 For part b) I don't understand how they use the area formula to gain the volume?
 
 Thanks

[99.00]

^Use sector of the circle minus triangle.

[BubbleWrapMan]

Area of sector =    (since is the proportion of the circle that the sector takes up)

Area of triangle =    (rule for area of a triangle)

Therefore cross-sectional area =

[martin1106]

 umm.. but how does the cross sectional area relate to the volume in this case??

[BubbleWrapMan]

Length times cross-sectional area.

Wait, that would make it which isn't what I got. But I think their "show that" thing is wrong.

[martin1106]

Length times cross-sectional area.

Wait, that would make it which isn't what I got. But I think their "show that" thing is wrong.

I think they made an error..not a good question.. Also, could u help me with this MC question?? I work out the answer B and C are both correct. the solution also states that B and C have the same answer but weird....they suggest C is the only answer