I've been stuck on this related rates problem for a while now and I just can't figure out how to even approach it. The problem goes something like this:
The above diagram shows two objects moving at different speeds. Both objects are 0.5 miles from the origin. The blue object is moving at 50mph. The straight-line distance between the blue object and the red object is increasing at a rate of 35 mph. Find the speed of the red object.
I tried to solve it using Pythagorean Theorem and finding the derivative of the top side of the triangle. Anyway, I ended up getting a negative number, and even ignoring the sign, the answer I got was obviously wrong. I know the speed of the red object is obviously greater than the blue object because the distance between the objects is increasing. I just really don't know how to calculate the magnitude of said number. There's also a variation of this problem where the straight-line distance is changing at a rate of -35mph but I think that should be doable once I understand how to go about solving the original. Any responses would be appreciated!