# Math formula python interpretation

I’ve been trying to convert this math formula into python.

So basically the approximation of 1/math.pi.

I tried making this iteration with

``````import math

N = 132
for k in range(1, N+1):
print("The N value is",N , end="\r", flush=True)

rec_pi_approximate = (2*math.sqrt(2)/9801) * N * ((math.factorial(4*k) * (1103+26390*k))/((math.factorial(k)**4) * (396**4*k)))
``````

But my values have been weird and I need guidance on how to actually type the formula and make a summation loop for it. Currently I am trying to find the reciprocal of pi with this formula equivalent to 1/math.pi

### >Solution :

The idea with the `for` loop is that you add up a part of the summation on each iteration. So you should keep track of the total sum so far and add to it each time.

``````import math
N = 132
pi_approximate_inv = 0
for k in range(0, N+1):
print("The N value is", k)
pi_approximate_inv += (2*math.sqrt(2)/9801) * ((math.factorial(4*k) * (1103+26390*k))/((math.factorial(k)**4) * (396**(4*k))))
print("The pi approximate is", 1.0/pi_approximate_inv)
``````

You also missed some parentheses at `(396**(4*k))` which I added. Also, it should be `print("The N value is", k)` (`k` not `N`) because it is showing what the summation would be if it stopped right there at `k`.

Because of floating point precision limits, it appears to max out at N=2.