Question

Write three terms of the GP when the first term ‘a’ and the common ratio ‘r’ are given?
(i) a = 4; r = 3 (ii) a = √5 ; r = 1/5
(iii) a = 81; r = −1/3 (iv) a = 1/64; r = 2

Answer 1

standard form of a GP is given as..

a , ar , ar² , ar³ , ar⁴ , ........ arⁿ, where a is first term and r is common ratio.

here, ar = 2nd term of the GP

ar² = 3rd term of the GP.

(1) a = 4, r = 3

so, first term = a = 4

2nd term = ar = 4 × 3 = 12

3rd term = ar² = 4 × 3² = 36

(2) a = √5, r = 1/5

first term = a = √5

2nd term = ar = √5 × 1/5 = 1/√5

3rd term = ar² = √5 × 1/5² = 1/5√5

(3) a = 81 , r = -1/3

first term = a = 81

2nd term = ar = 81 × -1/3 = -27

3rd term = ar² = 81 × (-1/3)² = 9

(4) a = 1/64 , r = 2

first term = a = 1/64

2nd term = ar = 1/64 × 2 = 1/32

3rd term = ar² = 1/64 × (2)² = 1/16

Answer 2

Answer:

hope that it will helps you