Question

Which of the following forms an AP? If they form AP then write next two terms?(i) 4, 10, 16, 22, . . . (ii) 1, – 1, – 3, – 5, . . . (iii) – 2, 2, – 2, 2, – 2, . . .(iv) 1, 1, 1, 2, 2, 2, 3, 3, 3, . . . (v) x, 2x, 3x, 4x ......

Answer 1

AP Series:A series is said to be AP if it is given as,

a,a+d,a+2d,a+3d,.......

Where a is first term and d is common difference.

(i) 4, 10, 16, 22, . . .

a=4 and d = 6.Hence,next two terms are 4+4*6=30 and 4+5*6=34.

(ii) 1, – 1, – 3, – 5, . . .

a=1 and d is -2.Hence, Next two terms are 1-4*2=-7 and 1-5*2=-9

(iii) – 2, 2, – 2, 2, – 2, . . .

Not AP

(iv) 1, 1, 1, 2, 2, 2, 3, 3, 3, . . .

Not AP

(v) x, 2x, 3x, 4x ......

a=x and d=x.Hence,next two terms are 5x and 6x.