Strange angle differentiation
Ok first time being here but I could use some help. The problem is this.
-There are 2 blood vessels seperated by angle X
-These two blood vessels have radii of R and r respectively
-The length "a" is the length of the primary blood vessel while the height "b" is the length from the end of the primary blood vessel to the branching vessel.
-The resistance to blood flow is as follows:
-R,r,a, and b are all constants.
-Which angle "x" would provide the least resistance of blood?
I worked out the derivative to look like
But I have no idea how to get a minimum of resistance since the only angles to make this 0 or undefined are angles such as 0 90 or 180 which are not the answers. Have I done something wrong in my derivative? Is there a specific answer?