(In reply to
Puzzle Solution by K Sengupta)
Both Matlab and Wolfram Alpha have a negative sign on the imaginary part of the complex solutions:
Matlab:
>> syms x
>> eq = 2*x-x^3 == 3i
eq =
- x^3 + 2*x == 3i
>> sx=solve(eq,x)
sx =
1i
- 11^(1/2)/2 - 1i/2
11^(1/2)/2 - 1i/2
making the three solutions
x = i
x = -sqrt(11)/2 - i/2
x = sqrt(11)/2 - i/2
and
Wolfram Alpha:
x = i
x = 1/2 (-sqrt(11) + -i)
x = 1/2 (sqrt(11) + -i)
Wolfram Alpha also provides further clarification:
(2x-x^3 - 3i) / (x-i) = -(x^2 + i x - 3) = -x^2 - i x + 3
Edited on April 28, 2023, 3:45 pm
|
Posted by Charlie
on 2023-04-28 14:18:21 |