To determine all real and complex solutions of the
equation, we'll have to determine the indefinite integral from the left side, for the
beginning.
Int (4x^3+6x)dx = 4Int x^3 dx + 6Int x
dx
Int (4x^3+6x)dx = 4x^4/4 + 6x^2/2 +
C
Int (4x^3+6x)dx = x^4 +
3x^2
We'll substitute the integral from the left side by
it's result:
x^4 + 3x^2 =
10
We'll subtract 10 both
sides:
x^4 + 3x^2 - 10 = 0
It
is a bi-quadratic equation. We'll put x^2 = t.
t^2 + 3t -
10 = 0
We'll apply quadratic
formula:
t1 =
[-3+sqrt(9+40)]/2
t1 =
(-3+7)/2
t1 = 2
t2 =
(-3-7)/2
t2 = -5
x^2 = t1
=> x^2 = 2
We'll take square root both
sides:
x1 = -sqrt2
x2 =
sqrt2
x^2 = t2 => x^2 =
-5
We'll take square root both
sides:
x3 = -isqrt5
x4 =
isqrt5
The real and complex roots of the
given equation are; {-sqrt2 ; sqrt2 ; -isqrt5 ;
isqrt5}.
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