Raise to non-integer exponent in bash?

Question

How to raise a number to a non-integer exponent in bash?

For example, this:

 echo $((10**0.25))

works in zsh, but in Bash it gives the following error:

-bash: 10**0.25: syntax error: invalid arithmetic operator (error token is ".25")

Answer 1

Bash supports only integer arithmetic. You have many alternatives, one of them is awk:

awk 'BEGIN {print 10**0.25}'

Answer 2

The good old standby bc works as well

$ echo "e(0.25*l(10))" | bc -l
1.77827941003892280121