SOLUTION: Solve: X^4 + 100 = 0 The problem is that the students only have factoring, irrational, and complex numbers as their background. Let a = x^2 a^2 = -50 a = 5i*{sqrt(2)}

Algebra.Com
Question 663690: Solve:
X^4 + 100 = 0
The problem is that the students only have factoring, irrational, and complex numbers as their background.
Let a = x^2
a^2 = -50
a = 5i*{sqrt(2)}
x^2 = 5i*{sqrt(2)}
How to find x?
Use synthetic division and guess? That doesn't seem to work too well either?
Recommendations for new Algebra II students? Thanks.

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
Solve:
X^4 + 100 = 0
-----------------

Use DeMoivre's Theorem
x^4 = 100cis(180) + n*360
x = sqrt(10)cis(45) + n*90
x = sqrt(10)cis(45), ...cis(135), cis(225), cis(315)
----------
Probably more than Algebra 2 can do, tho.
--> not an appropriate problem for Algebra 2.

RELATED QUESTIONS

Hello can you please help me classify the given numbers as real and rational, real and... (answered by stanbon)
Classify the given numbers as real and rational, real and irrational, or complex. a.)... (answered by stanbon)
1.Use factoring and the zero product property to solve the question.... (answered by stanbon,ewatrrr)
Classify the given numbers as real and rational, real and irrational, or complex.... (answered by richard1234)
classify the given numbers as real and rational, real and irrational, or complex... (answered by jsmallt9,richard1234)
classify the given numbers as real and rational, real and irrational, or complex... (answered by stanbon)
Solve for all (including irrational and complex roots if any) x in the equation... (answered by Edwin McCravy)
Evaluate the discriminant for the following... (answered by josgarithmetic)
Classify as rational, irrational or complex (80)^(1/5) my answer rational (16)^(1/4) my (answered by jim_thompson5910)