Guys, mind explaining why is the answer B but not D?

Guess that you have justified it with the sketch diagram on the upper right corner. What else do you want?

Remember this: A good explanation doesn’t contradict established knowledge.

Nope, but close enough.

Just to make sure, cause the answer given by the book is B instead of D.

And I'm scared that it may be something that I may had mislearnt or left out during my revision.

I jumped to conclusion that you're from bu3 when I saw your twitter tab in the picture of your results

Hey guys, I got more tips for SEJ SPM (paper 2 IIRC), For form 5 Tema 10 focus on Bab 2 subtopic, Gerakan Islah, Akhbar-akhbar and perjuangan persatuan-persatuan melayu. Tema 11 focus on Bab 5, sistem ahli, bab 6 , pembentukan Malaysia, Akta Malaysia and for bab 8 Memartabatkan BM and Dasar kebudayaan. For Tema 12(bab 9) look out for Dasar Luar Malaysia and Cabaran Masa depan especially K Ekonomi and K masyarakat.

Hope this helps

Okay whatever floats your boat...if you insist I am BU3 then BU3 I am to you then.

So, umm, did you get an explanation on why the answer is B? I also don't get it.

I was just saying. Haha, I'm sorry if I offended you!

Now that's gonna be a hard one.

Sorry guys if someone could help me out with this question:
http://img513.imageshack.us/img513/3449/wjif.jpg

My phone's camera quite sucks im sorry about that The value is (k-3)i+j in case its not clear enough.
Anyone know how to do this?The answer is (k-3)^2 +1=1,hence k=1(final answer)

Does Pythagoras' Theorem remind you of anything ?

B is the right answer . Where did you get this from ? I have past years before the year 2000 , but in B.M .

Why B? I have done similar ones before too.

Yea the unit vector formula i do know that.But im stuck on that.How could i apply unit vector formula into it?

I have done this before too . My teacher said cancel PQ coz its an error. Solution is like this:


Attached thumbnail(s)

Given that

Vector PQ = (k − 3) i + (1) j

and

Vector PQ is a unit vector. (The hidden message is the magnitude |PQ| = 1)

Therefore,

|PQ| = √(x² + y²)

and you finish the rest...

This post has been edited by Critical_Fallacy: Oct 5 2013, 10:15 PM

D should be the correct answer. Since R, the resistance, is acting to the direction opposite of the motion of the ship, the resultant force should be the (horizontal force of two ships, 2F cos angle) - R. If you take F sin angle, you'll be taking the vertical motion of the ship.

A big thanks to both of you. So does the phrase "........is a unit vector" means its equal to 1 in any circumstances?

Yea for unit vector, it means magnitude is 1

To be safe, it can be shown that the magnitude of the resultant force, T = 2F cos 30° by applying the law of cosines on the addition of vectors (construct the parallelogram).