A boat that can travel at 4.0km/h in still water crosses a river with a current of 2.0 km/h. At what angle must the boat be pointed upstream (that is, relative to its actual path) to go straight across the river?
No equations were given but it seems like a simple trig problem, just can't get the right answer
The Attempt at a Solution
My first attempt i used inverse tan theta (4/2) and got an angle of 63
My second attempt i used inverse cos theta (2/4) and got an angle of 60
the actual answer is 30. Either there is a very big step i'm missing or i've drawn something horribly wrong.