Can someone explain to me why the program prints "false"?

Question

From math import sqrt
Print(sqrt(3)*sqrt(3)==3)

Answer 1

If you look at the output of:

print(sqrt(3)*sqrt(3))

You get the following:

2.9999999999999996

This is a floating point precision problem with sqrt() in Python that has to be handled by the user.

I haven't tried it myself, but you could try the library mpmath, or make your own sqrt function using import decimal.

Answer 2

All languages have default precision problems (libraries help)...related to base-2 (binary) architecture.

Various demos below...the first is direct, the second is an 'explorer', the third shows a 'precision delay' when trying to match a float (the point is: in another base...other than base 10...it doesn't always succeed).

https://code.sololearn.com/ckZEfBRiUrEA/?ref=app
https://code.sololearn.com/WYCTOysAGnLv/?ref=app
https://code.sololearn.com/cIC8qOLAfL7m/?ref=app

Answer 3

# It's a general thing to be aware of with floats
# try this in the python playground to see another example.
print(0.1+0.2)

# or open the developer tools on a browser
# and try 0.1 +.0.2 in the console to see the
# same issue with javascript

Answer 4

it is because you use == operator