Output is giving me "Empty sym: 0-by-1"

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Nicholas Gillam
Nicholas Gillam 2019-11-11
回答： Walter Roberson 2019-11-11
syms s
g = (s^2-2*s+2)/((s+2)*(s+4)*(s+5)*(s+6))
x = diff(g)
b = roots(x)
I'm trying to solve for the roots of the differentiated function, but I'm getting the "Empty sym: 0-by-1" output, and I'm unsure why. I've followed the syntax on how everything should be, but I don't know why this is being outputted.

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采纳的回答

Walter Roberson
Walter Roberson 2019-11-11
roots() is not explicitly defined for symbolic expressions, and will not work for scalar symbolic expressions. It is also only defined for polynomials, but g is not a polynomial. Instead use
b = solve(x);

更多回答（1 个）

JESUS DAVID ARIZA ROYETH
solution:
syms s
g = (s^2-2*s+2)/((s+2)*(s+4)*(s+5)*(s+6))
x = diff(g)
b = double(solve(x))

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