# Carrotsticks' MX2 HSC 2013 Solutions (1 Viewer)

#### Carrotsticks

##### Retired
Bump. Is my solution valid?
You said that the arg was inverse tan ....

Are you sure this is always true?

#### Makematics

##### Well-Known Member
You said that the arg was inverse tan ....

Are you sure this is always true?
wait why isn't it? Sorry i've forgotten a lot over the past two months hahaha

#### Carrotsticks

##### Retired
Consider the arg of -1-root(3)i.

#### Makematics

##### Well-Known Member
Consider the arg of -1-root(3)i.
hmmm yeah I get what you mean, but how come the answer still comes out?

EDIT: But the question tells you the complex numbers are both in the first quadrant, right?

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bump

#### anomalousdecay

wait why isn't it? Sorry i've forgotten a lot over the past two months hahaha
Same here haha. I've forgotten stuff in Chem and Physics, but somehow math is ok.

Oh yeah and bump for the question of course.

#### Makematics

##### Well-Known Member
Oh yeah and bump for the question of course.
Thanks lol, im still curious as to why i lost two marks

#### anomalousdecay

Thanks lol, im still curious as to why i lost two marks
Maybe discuss it next week at the meet.

I still don't know how to do that question or mechonics lol.

#### Trebla

Same here haha. I've forgotten stuff in Chem and Physics, but somehow math is ok.

Oh yeah and bump for the question of course.
Think about the range of the inverse tan function

Maybe a scan of what was written might help?

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#### QZP

##### Well-Known Member
Why is file gone :{

#### mreditor16

##### Well-Known Member
Carret, I think there is a typo with Q16 b) v)....

Shouldn't your definition of b be such that b is the length of the semi-minor axis? You define it as the length of the minor axis, which should be 2b, no?

Tell me if I'm wrong

bumpity bump

#### mreditor16

##### Well-Known Member
Carret, I think there is a typo with Q16 b) v)....

Shouldn't your definition of b be such that b is the length of the semi-minor axis? You define it as the length of the minor axis, which should be 2b, no?

Tell me if I'm wrong
bumpity bump

#### Carrotsticks

##### Retired
Carret, I think there is a typo with Q16 b) v)....

Shouldn't your definition of b be such that b is the length of the semi-minor axis? You define it as the length of the minor axis, which should be 2b, no?

Tell me if I'm wrong
In which case, it should be "Semi-minor axis". Cheers =)

#### mreditor16

##### Well-Known Member
In which case, it should be "Semi-minor axis". Cheers =)
okay, thanks for confirming. I just wanted to check I wasn't doing something stupid. thanks!