Olly_s15 Question Thread

[olly_s15]

Just need some help with the following:

If is a factor of , find the remaining factors.

I know that the conjugate is also a factor but cannot find the remaining.

[the.watchman]

So the first two factors are (z-3i) and (z+3i)

This is probably a bad way but, using quad. formula:



OR

From this, you can get the other factors, which are:

AND

[GerrySly]

You just expand then divide by that. That'll give you another quadratic which you can then factorise the way you want it

[the.watchman]

Oops, I forgot to show the first few steps:

Divide the expression by to get ,

Then solve (as in my previous post)

Sorry about that

[olly_s15]

Im having troubles dividing the expression because there is no z term when i make the expansion

[the.watchman]

Im having troubles dividing the expression because there is no z term when i make the expansion

If you're using long division (or even other methods) just put a 'ghost' term 0z into the divisor

[olly_s15]

Omg, I see. Brain not working. Thanks

[the.watchman]

Omg, I see. Brain not working. Thanks

No prob.
Somehow, my pea-sized knowledge of complex numbers got me through that one (phew! )

[olly_s15]

Find the square root of in cartesian form.

[superflya]

let

 hence

now to find ur






and now combine

[olly_s15]

zzzz i made a mistake.. thought inverse tan of root 3 was pi/4. stupid

[superflya]

zzzz i made a mistake.. thought inverse tan of root 3 was pi/4. stupid

lol it happens.

[olly_s15]

thanks though

[superflya]

not a prob, its good practice for me anyway

[olly_s15]

Hey guys, need help with question 2f of this one.

See attached file. Thanks.