How do you simplify sqrt41?

1 Answer
Jun 11, 2017

sqrt(41) ~~ 6.4031242374 is an irrational number which cannot be simplified.

Explanation:

41 is a prime number, so has no square factors.

As a result its square root cannot be simplified. It is an irrational number.

We find:

6^2 = 36 < 41 < 49 = 7^2

So:

6 < sqrt(41) < 7

To get a good approximation for sqrt(41) note that:

64^2 = 4096

So:

sqrt(41) ~~ sqrt(40.96) = 6.4 = 32/5

In general:

sqrt(a^2+b) = a+b/(2a+b/(2a+b/(2a+...)))

Putting a=32/5 and b=1/25, we find:

sqrt(41) = 32/5+(1/25)/(64/5+(1/25)/(64/5+(1/25)/(64/5+...)))

We can get rational approximations for sqrt(41) by truncating this continued fraction.

For example:

sqrt(41) ~~ 32/5+(1/25)/(64/5) = 2049/320

sqrt(41) ~~ 32/5+(1/25)/(64/5+(1/25)/(64/5)) = 131168/20485 ~~ 6.4031242374