How can I recognize symbolic value with actual value 0?

I was making some calculation and got symbolic value of

ans =

3/2 - (73^(1/2)/4 - 7/4)*(73^(1/2)/4 + 7/4)

it was actually 0, but matlab didn't recognize it. I used double(syms), but the result was

ans =

-4.5278e-72

how can I make matlab recognize it as 0?

Answer 1

[Walter Roberson]

simplify() the expression

[Hansol Lee]

thank you!

Answer 2

[Paresh yeole]

You need to specify custom tolerance.

if abs(ans) < 1e-10
    ans = 0;
end

You can specify your own tolerance instead of 1e-10.