For each of the following sequences: • identify if the sequence is arithmetic, geometric or quadratic. Justify your response. • Assuming the first term of each sequence is a1, give an expression for...

For each of the following sequences:
• identify if the sequence is arithmetic, geometric or quadratic. Justify your
response.
• Assuming the first term of each sequence is a1, give an expression for ai. (In other words, find a formula for the i-th term in the sequence).
• if the sequence is arithmetic or geometric, compute the sum of the first 10 terms in the sequence. Show your work. If the sequence is quadratic, then show the work used to answer part (b).

(a) 3, 15, 75, 375,...
(b) 0, 4, 11, 21,...
(c) −6, 1, 8, 15,...