[NOTE: I mistakenly sent several replies to individuals rather than to
the group. Several are moot, but I did not want to leave them off-list.
So I am resending below. Sorry about that! Bruce]
Hi Oscar,
Thanks for the quick reply.
The symbol 'a' is declared to be real and positive. But my example is
NOT automatically simplified:
a=symbols('a', real=True, positive=True)
expr = sqrt(4*a**2 + 1)*sqrt(1/(4*a**6 - 15*a**4 + 12*a**2 + 4))
simplify(expr)
sqrt(4*a**2 + 1)*sqrt(1/(4*a**6 - 15*a**4 + 12*a**2 + 4))
Could you suggest how I might direct sympy to simplify it as shown
below? In my expressions, the arguments of the square roots are
typically polynomials in 'a', or ratios of such polynomials.
Cheers,
Bruce
On 01.04.21 18:53, Oscar Benjamin wrote:
On Thu, 1 Apr 2021 at 15:43, 'B A' via sympy <sympy@googlegroups.com> wrote:
What is described above has worked well for me. But there is a further
simplification step that I need help with.
I have some long expressions containing terms contain terms which look like
this example:
sqrt(4*a**2 + 1)*sqrt(1/(4*a**6 - 15*a**4 + 12*a**2 + 4))
How can I instruct sympy to combine such square roots and factor the arguments?
In this example that would lead to:
sqrt(factor((4*a**2 + 1)/(4*a**6 - 15*a**4 + 12*a**2 + 4)))
=
1/Abs(a**2 - 2)
You can declare a to be real:
In [12]: a = Symbol('a', real=True)
In [13]: expr = sqrt(factor((4*a**2 + 1)/(4*a**6 - 15*a**4 + 12*a**2 + 4)))
In [14]: expr
Out[14]:
1
────────
│ 2 │
│a - 2│
Oscar
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