Question: `sqrt(2), 3sqrt(4)` and` 4sqrt(6)` in ascending order are :
A
B
C
D
`sqrt(2), 3sqrt(4), 4sqrt(6)`
B
`4sqrt(6), sqrt(2), 3sqrt(4)`
C
`4sqrt(6), 3sqrt(4), sqrt(2)`
D
`sqrt(2), 4sqrt(6), 3sqrt(4)`
Note: Given surds are of order 2, 3, 4 whose 1 c. m. is 12 Changing each one of given surds to that of order 12 we get :
`sqrt(2) = 2^(1/2) = 2^(1/2 xx 6/6)`
`= (2^6)^(1/12) = (64)^(1/12)`
`= 3sqrt(4) = 4^(1/3) = 4^(1/3 xx 4/4)`
`= 4^(4/12) = (4^4)^(1/12)`
`= (256)^(1/12)`
`= 4sqrt(6) = 6^(1/4)`
`= 6^(1/4 xx 3/3) = 6^(3/12)`
`= (6^3)^(1/12) = (216)^(1/12)`
Now,` (64)^(1/12) < (216)^(1/12) < (256)^(1/12)`
`:. sqrt(2) < 4sqrt(6) < 3sqrt(4).`