Approach speed remains largely unchanged. However, if you want to get into tan/sin/cos etc, try and figure out the crosswind and headwind components.
On the other hand, as a rough rule of thumb try the following:
If the wind is 30deg off rw hdg then the crosswind component is 30 minutes around the clock - ie half.
If the wind is 45 deg off head it is 45 minutes around the clock - 3/4
finally, if the wind is 60 deg off rw hdg it is 60 minutes around the clock - whole.
The maths isn't quite right but it sure is good enough for government work
