3. For every real number a define a function ha: R {0} R by ha(7) = || ||0 (a) (6 points) Verify that the partial derivatives of these functions ha with respect to the variables xj (for j = 1, ..., n) are given by aha axjha-2. ; (b) (4 points) Assuming n + 2, find a nonzero number a (which should depend on n; for partial credit just do the case n = 3) so that ha is harmonic. 3. For every real number a define a function ha: R {0} R by ha(7) = || ||0 (a) (6 points) Verify that the partial derivatives of these functions ha with respect to the variables xj (for j = 1, ..., n) are given by aha axjha-2. ; (b) (4 points) Assuming n + 2, find a nonzero number a (which should depend on n; for partial credit just do the case n = 3) so that ha is harmonic