Please prove both excercsises by induction.

4.3. Show that the sum of the first n squares is given by 2 n(n+1)(2n 1) 6 k-1 for all n>1 4.4. Show that the sum of the first n cubes is given by k3 1323 + + n3- (1 2n) 2 n2(n +1)2 k-1 for all n > 1