Hi

I need help on the following equation:

1)

use quadratic equation:

i get

or

my question is do i simplify this to find the roots or leave it?

P.S

Printable View

- November 3rd 2010, 02:48 AMPaymemoneyComplex Number finding the roots
Hi

I need help on the following equation:

1)

use quadratic equation:

i get

or

my question is do i simplify this to find the roots or leave it?

P.S - November 3rd 2010, 03:51 AMProve It
I think completing the square might be better in this case...

From here, you should convert to polars to find the four values of . - November 3rd 2010, 07:55 AMHallsofIvy
- November 3rd 2010, 09:46 AMSoroban
Hello, Paymemoney!

Your arithmetic is off . . .

Quote:

1) Solve: .

Let:

Substitute:

Use Quadratic Formula: . .no

Did you forget the Quadratic Formula?

For the roots are: .

. . . . . .

Back-substitute: .

. . Therefore: .

- November 3rd 2010, 02:33 PMPaymemoney
oops yeh my bad, my quadratic equation was the mistake

- November 3rd 2010, 03:29 PMPaymemoney
Just a quick question if i had something like this how would i find the roots

This is what i have done

what would you do next? - November 3rd 2010, 03:34 PMmr fantastic
- November 3rd 2010, 03:40 PMmr fantastic
It's very clear that z = -1 is a solution to . Therefore z + 1 is a factor. Divide z + 1 into to get a cubic factor. It is very clear that z + 1 is also a factor of the cubic. Divide it into the cubic to get a quadratic factor. Factorise the quadratic in the usual way.

From the factor you get the solutions. There is sure to be examples like this in your class notes and textbook. Go back and review this material.