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AQA FP1 (1st June)

I got full marks in all the questions except 5 and 7.. I think I dropped 3 marks on question 7 and around 6 on question 5 :/

Reply 381

Lilliesha

TheEd

I didn't get this in the exam but my teacher said today that you put the imaginary part = 0 so 4x -4 = 0 => 4x = 4 => x=1 which is the only value. Makes sense.

I didn't get it either... I just made the real part equal to zero and got some number that surely isn't right...
I also combine the real and imaginary part together and tried that but pretty sure that's not right either.

Reply 382

TheEd

Lilliesha

I didn't get it either... I just made the real part equal to zero and got some number that surely isn't right...
I also combine the real and imaginary part together and tried that but pretty sure that's not right either.

Funny that I went through those two processes as well which were both doomed to failure! :frown:

Reply 383

Lilliesha

TheEd

Funny that I went through those two processes as well which were both doomed to failure! :frown:

Failure on that part of the question yes...
I just want someone who knows that is the definite answer (4x-4=0) or anything else that could please explain because in all the other questions that I've lost marks on I realise why except this one.

Reply 384

abcxyz6666

2

Lilliesha

Failure on that part of the question yes...
I just want someone who knows that is the definite answer (4x-4=0) or anything else that could please explain because in all the other questions that I've lost marks on I realise why except this one.

well it was 4ix - 4i = 0 you took out both i gives 4x -4 =0

Reply 385

Lilliesha

abcxyz6666

well it was 4ix - 4i = 0 you took out both i gives 4x -4 =0

Hmm I suppose...

Reply 386

abcxyz6666

2

Is it not in your text book, it should be

Reply 387

Lilliesha

abcxyz6666

Is it not in your text book, it should be

Probably.

Reply 388

pcfailure

TheEd

I've scanned in the paper. See Attachments for images of the pages. :smile:

Thanks for uploading :smile:

Reply 389

josh5702

Anyones teacher given them any sort of mark scheme or anything like that for all or parts of the exam cos i would really love to know the answer from a teacher for that complex numbers one

Reply 390

Adam92

13

josh5702

Anyones teacher given them any sort of mark scheme or anything like that for all or parts of the exam cos i would really love to know the answer from a teacher for that complex numbers one

Part b)?

Just set the imaginary part to 0.

Reply 391

josh5702

Adam92

Part b)?

Just set the imaginary part to 0.

well what did you get for z(squared) -2z

Reply 392

Adam92

13

josh5702

well what did you get for z(squared) -2z

z^2 + 2z* you mean?

It's x^2 + 2x - 4 + 4xi - 4i.

Set the imaginary part to 0, so 4x - 4 = 0, hence x = 1 :smile:

Reply 393

Languagesfreak

13

That complex numbers question confused me at first as well :O At first I tried to set the real part to 0, d'oh! Then I realised it was the imaginary part I had to set to 0.

Reply 394

josh5702

Adam92

z^2 + 2z* you mean?

It's x^2 + 2x - 4 + 4xi - 4i.

Set the imaginary part to 0, so 4x - 4 = 0, hence x = 1 :smile:

ah right didnt get that at all
i just had a quadratic liike i put x^2 + (4i+2)x +(-4-4i)=0
so when it said there was one solution i thought that meant work out the discriminant and it should equal 0 but it just didnt so never got anywhere, only 2 marks lost