# Why is d2 invalid?

Can someone please help me with this? Why is the line with d2 invalid syntax?

```
def put_value(S, K, sigma, T):
d1 = ((np.log(S / K) + (T * 0.5 * sigma * sigma)) / (sigma * np.sqrt(T))
d2 = d1 - (sigma * np.sqrt(T))
put = (norm.cdf(d2, 0.0, 1.0) * K) - (norm.cdf(d1, 0.0, 1.0) * S)
return put
```

## Have an answer?

JD