Fitzpatrick Question I don't get (plus general help needed as well) (1 Viewer)

[Shadowdude]

Before anyone goes "OMG FITZPATRICK IS SO GAY", I have the Cambridge book. It's just that my teacher advocates the use of Fitzpatrick. Still, the more textbooks the better. This is the basis of my first question.

I have Cambridge 4u, and will soon get from the school Fitzpatrick 4u. Any other books I should get? Excel Study Guides? Terry Lee?

And of course, the question I don't get... from homework:

Exercise 31(b) Question 32:



Once I can do this, I suppose I could be able to crawl my way through the rest.

 

[jet]

Can you complete the question?

 

[lychnobity]

I'd recommend Terry Lee's book - it has solutions...

But don't use it for learning purposes. Use it only for the questions, more examples or alternative methods.

 

[Aquawhite]

I saw this question in complex numbers when I was doing work as well. The question is in itself kind of pointless. It doesn't ask anything from you to prove. Just skip it, I think it was a small printing error.

@ jetblack - that was the whole question ...

 

[Shadowdude]

^ What he said. That's the entire question.

Even more confusing when my teacher marked it (on a printout, textbooks are delayed) and told us to "Do those ones marked, because I've done them already, and therefore can help you if you get stuck."

Now I'm wondering how he did it.

---

So Terry Lee... mmkay. Wouldn't that be a bit overboard though, with Fitzpatrick, Cambridge and Terry Lee, plus past papers?

 

[jet]

Hahahah lol, sorry. You wonder whether the authors actually read what they wrote...

 

[gurmies]

As if you can't do this question...?

 

[ninetypercent]

if u really want to know, The question is actually:

let z1 = x1 + y1i
z2 = x2 + y2i
z3 = x3 + y3i

Prove that z1 + z2 = z2 + z1

i found question 32 pointless. its obvious that z1 + z2 = z2 + z1.
gahhh

 

[untouchablecuz]

commutative law is pretty important

but then again, isnt it just a definition? you can't prove a definition

 

[gurmies]

Uh, I think you prove it in first year algebra using vector stuff.

 

[Shadowdude]

How'd you find out what the question was?

 

[Trebla]

if u really want to know, The question is actually:

let z1 = x1 + y1i
z2 = x2 + y2i
z3 = x3 + y3i

Prove that z1 + z2 = z2 + z1

i found question 32 pointless. its obvious that z1 + z2 = z2 + z1.
gahhh

Even though it is obvious, it is a property of complex numbers. It's meant to make you realise that arithmetic in complex numbers (this "brand new" number system that's completely foreign to you) is much the same as in real numbers.

 

[ninetypercent]

How'd you find out what the question was?

fitzpatrick solutions from the stickied thread.

 

[Dragonmaster262]

Find

 

[Trebla]

lol, how random. The integral is equivalent to integrating cos²x which can be converted into a integrable form by using the double angle formula for cosine.

 

[Dragonmaster262]

I don't get how it's equivalent to

 

[tacogym27101990]

I don't get how it's equivalent to

sin and cos are complementary. you know how sin(pi-x) = cosx? same thing

 

[addikaye03]

sin and cos are complementary. you know how sin(pi-x) = cosx? same thing

sin(pi/2-x) **

To dragonmaster:

Draw a right angled triangle, have one angle as x, therefore the other is pi/2-x, see that sin(pi/2-x)=cosx?

 

[Dragonmaster262]

Oh yeah I forgot about that; thanks guys.