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 = (2×12) − (3×1) + 5 = 4
T2 = (2×22) − (3×2) + 5 = 7
T3 = (2×32) − (3×3) + 5 = 14
T4 = (2×42) − (3×4) + 5 = 25
T5 = (2×52) − (3×5) + 5 = 40
T20 = (2×202) − (3×20) + 5 = 745
