fp1 complex numbers

Just to clarify would the answer for the first question be X= 3, 1+/- root-1 or i all over 2?


Posted from TSR Mobile

Yes.

I get $z=1+\lambda i$, i'll check.
Are you having trouble getting started?
I get $w=\lambda + i$.
My method was quite long but with these answers coming out so nicely it looks right, although I haven't checked.
EDIT. These are correct.
Do you need a hand on how to start?

Yes please. The answer in the book is only the answer to z.
Just summarise what you did to get to the answer in steps like an algorithm and I'll follow through.

Posted from TSR Mobile.

That's close, sorry I was late to see this.




Posted from TSR Mobile

Right, does using the quadratic formula work too?

Completing the square and using formula are equivalent, they both will always work for any quadratic.

Is it quicker to complete the square?

Is it quicker to complete the square?

Depends, for simple examples it can be. But sometimes if there are square roots and complex numbers as coefficients,the quadratic formula would probably be quicker. I normally complete the square.

I would e used the quadratic formula in the exam. It seems much faster.


Posted from TSR Mobile

To begin with I found w in terms of lambda and z, from the second equation. Then I subbed in the expression for w into the first equation and just simplified. It is very fiddly and your algebra needs to be good, and make sure you don't make sign errors with the i's.

Where did I go wrong...




Posted from TSR Mobile

Depends, for simple examples it can be. But sometimes if there are square roots and complex numbers as coefficients,the quadratic formula would probably be quicker. I normally complete the square.

You've got it, notice there is a common factor on the numerator of $\lambda ^2 + 1$.

You've got it, notice there is a common factor on the numerator of $\lambda ^2 + 1$.

Love you. Solved it, **** yes.


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