What are the solutions of the equation x4 + 6x2 + 5 = 0? Use u substitution to solve.
Solution:
Given: Equation is x4 + 6x2 + 5 = 0
Let x2 = u then the given equation becomes u2 + 6u + 5 = 0
This is in the form ax2 + bx + c=0
We can solve by using quadratic formula for finding roots
x = {-b ± √(b2 - 4ac)} / 2a
Here, a = 1, b = 6, c = 5
u = {-(6) ± √((6)2 - 4(1)(5))} / 2(1)
u= {-6 ± √(36 -20)} / 2
u = {-6 ± √16}/2
u = {-6 ± 4} /2
u = -1, or u = -5
x2 = u
x = ±√u
x = ±√-1 or x = ±√-5
x = ±i or x = ±√5i
The solutions are + i, -i , +√5i, -√5i for the given equation.
What are the solutions of the equation x4 + 6x2 + 5 = 0? Use u substitution to solve.
Summary:
The solutions are + i, -i , +√5i, -√5i of the equation x4 + 6x2 + 5 = 0
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