WAEC - Mathematics (1991 - No. 22)
The first term a of an A.P is equal to twice the
common difference d. Find, in terms of d, the 5th
term of the A.P.
common difference d. Find, in terms of d, the 5th
term of the A.P.
4d
5d
6d
a + 5d
2a + 4d
ব্যাখ্যা
Tn = a + (n - 1)d; AP; a = 2d; Tn = 2d + (n - 1)d
T5 = 2d + (5 - 1)d = 2d + 4d = 6d
T5 = 2d + (5 - 1)d = 2d + 4d = 6d