Problem!

1. Two sources of heat are placed s meters apart – a source of intensity a at A and a source of intensity b at B. The intensity of heat at a point P on the line segment between A and B is given the formula

I= a/x^2 + b/〖(s-x)〗^2

where x is the distance between P and A measured in meters. At what point between A and B will the temperature be lowest?

2. Find the distance D(x) from a point (x,y) on the graph of f(x)=4-x^2 to the point P(4,3). Draw the graph of D and then use the trace function to estimate the point on the graph of f closest to P.

Please help. This will contribute in my final grade.