Resources that can be saved through the use of computers​

How do we use the sumif formula (when dealing with different formats) ?

For positive constants a and b, the force between two atoms in a molecule is given f(r) = −a r2 + b r3 , where r > 0 is the distance between the atoms. note: a and b are upper case letters. (a) find f '(r) = (b) find the critical point for f(r). r = (c) find f ''(r) = (d) find the value of r so that f ''(r) = 0.

The a great imaginary circle, or reference line, around earth that is equally distant from the two poles and divides earth into the northern and southern hemispheres.