Solve equations using De Moivre's theorem:

1. x^7 + x^4 + x^3 + 1 = 0

2. x^7 - x^4 + x^3 - 1 = 0

I tried multiplying with (x - 1). Also tried putting x^3 = y; didn't work.

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- November 22nd 2013, 11:54 PManil86Solve 7th degree equation using complex number
Solve equations using De Moivre's theorem:

1. x^7 + x^4 + x^3 + 1 = 0

2. x^7 - x^4 + x^3 - 1 = 0

I tried multiplying with (x - 1). Also tried putting x^3 = y; didn't work. - November 23rd 2013, 12:47 AMchiroRe: Solve 7th degree equation using complex number
Hey anil86.

Have you been able to factorize the expression in terms (ax + b)^n? (Hint: Consider (x+iy)^n where the real terms are x^7, x^4, x^3 and 1). - November 23rd 2013, 04:25 PMSorobanRe: Solve 7th degree equation using complex number
Hello, anil86!

I'll walk you through the first one . . .

Quote:

Solve equations using De Moivre's theorem:

Factor: .

Factor: .