Write your name to attest that this is your own original work: 3. Rewrite each expression using sigma notation. Do not evaluate. [4] a) 14+ 34 +54 + 74+ 94 + 114 [4] b) 3 3 4 + 5 5 6 001 - 6 [4] c) f(12) + f(23) + f(24) + ...+ f(12) 4. Evaluate each expression by hand. Use the formulas below if necessary. [4] a ) ( - 1 ) 1 k = 2 k - 1 40 [6] b) (k2 - 2k - 4) k = 1 12 _ n(n + 1)(2n + 1) 1 = n SK= n ( n + 1 ) 6 2 = 1 K = 1 k= 1