Advanced Search

Question: surd produces absurd result

Question:surd produces absurd result

max125 175 Maple 2016
August 22 2016
1

I am trying to solve an equation using surd and I get a strange result.

solve(surd(x^4,8)=-2)
    4, -4, 4 I, -4 I

These solutions are clearly wrong.

The equation (x^4)^(1/8) = -2 has no solution.

This problem is equivalent to asking the computer to solve sqrt(x) = -2

which has no solution in R or C.

 

However if I type

solve((x^4)^(1/8) = -2) , then I get no answer, which is what I expected.

Why does surd behave in this unexpected way.

 

Also another thing I am wondering, why doesn't Maple simplify (x^4)^(1/8) to x^(1/2).

I tried the simplify command it didn't work.

 
Please Wait...