Q4 of 176 Page 21

Find the geometric means of the following pairs of numbers :

i. 2 and 8


ii. a3b and ab3


iii. –8 and –2

(i) GM = √ab


Let a = 2 and b =8


GM = √2×8


= √16


= 4.


(ii) GM = √xy


Let x = a3b and y = ab3


GM = √ a3b × ab3


= √a4b4


= a2b2.


(iii) GM = √ab


Let a = –2 and b = –8


GM = √–2×–8


= √–16


[we know that √–1 = i(iota)]


= 4i.


More from this chapter

All 176 →
2

Insert 5 geometric means between 16 and .

3

Insert 5 geometric means between and .

 5

If a is the G.M. of 2 and find a.

 6

Find the two numbers whose A.M. is 25 and GM is 20.