Q1 First note that when , so is a factor...
Long dividing gives the quadratic factor .
Now factorise the quadratic factor to get the required result.
Q2: Express in polar form, then use DeMoivre's Theorem.
Under the section of complex number, i faced 2 questions which i couldn't answer... Here they go...
-Show that x=1-2i is a root of the equation x3-3x2+7x-5=0. Hence, find all the roots of the equation.
-Express in the form a+ib, where a>0
Note: for both question, 'i' represents imaginary number... Please show step-by-step working if possible... Thanks...
- Show that yields zero at .
- Hint for finding the rest of the roots: note that is also a root.
- For the second question, use De Moivre's theorem, as Prove It suggested.
Notes like this usually serve as a reminder for me not to spoon-feed detailed solutions!Please show step-by-step working if possible... Thanks..
Another way (without using polar form):
Fernando Revilla
Edited: Sorry, now I see that the problem was already solved this way.