Okay, so I have this question that has been killing me. This is it:
If f is the focal length of a convex lens and an object is placed at a distance p from the lens, then its image will be at a distance q from the lens, where f , p , and q are related by the lens equation
What is the rate of change of p with respect to q if q=4 and f=1 ?
So I've tried about a million approaches and I never get the right answer. I know you're supposed to show how you've attempted this problem, but I've tried so many ways I don't know which one to type on here. Basically, I'm hoping somebody will be able to give me a boot in the right direction because I actually haven't a clue as to how to even begin attacking this.