InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
If three positive real numbers a,b,c are in AP such that abc=4, then the minimum value of b is |
|
Answer» `therefore a,b,c " are in AP."` Let `a=A-D, b=A, c=A+D` Then, `a=b-D, c=b+D` Now, `abc=4` `(b-D)b(b+D)=4` `implies b(b^(2)-D^(2))=4` `implies b^(2)-D^(2)ltb^(2)` `implies b(b^(2)-D^(2)) lt b^(3) implies 4ltb^(3)` `therefore " " bgt (4)^((1)/(3))" or " bgt (2)^((2)/(3))` Hence, the minimum value of b is `(2)^((2)/(3))` |
|