1942 June 17 Convoy PQ-17 leaves Iceland for Murmansk – massive casualties from German onslaught during the trip. July 5 10 out of 27 ships reach Murmansk.
... a field of characteristic 2, the element 2a is zero and it is impossible to divide by it.)
The symbol
<math>\pm \sqrt {b^2-4ac}</math>
in the formula ...