In an Argand diagram O is the origin, P represents the number 7 – i and Q represent the number 12 + 4i.
Calculate the size of angle OPQ.
I’ve done 1st part but how can I calculate angle OPQ in this case?
You can find out the modulus and arg of P and Q.
After that,you have to find the angle POQ.
Then, use the cosine formula to calculate length PQ.
Last step is use sine formula to get the angle OPQ.