Let y be a piecewise function given by

y(r) =kr^2 − m, if r ≤ R;

−2kR^3 / r, if r > R

for some (k,m, r,R > 0) ∈ R. This function represents the gravitational potential of the Earth.

Find the values of k for which y is continuous at r = R.

any idea how to do this queation?

thank you!