This worksheet is about finding terms of a sequence from a formula with a quadratic term.
To find the first 5 terms and the 20th term of the sequence given by the formula
Tn = 2n2 − 3n + 5
we simply substitute different values for n.
The first term is called T1 , where n = 1.
The second term is called T2 , where n = 2 etc.
The twentieth term is called T20 , where n = 20.
Examples
T1 = 2×1 − 3×1 + 5 = 4
T2 = 2×4 − 3×2 + 5 = 7
T3 = 2×9 − 3×3 + 5 = 14
T4 = 2×16 − 3×4 + 5 = 25
T5 = 2×25 − 3×5 + 5 = 40
T20 = 2×400 − 3×20 + 5 = 745
