1.

If `a_1,a_2,a_3` are 3 positive consecutive terms of a GP with common ratio K . then all the values of K for which the inequality `a_3>4a_2-3a_1`, is satisfiedA. `1ltrlt3`B. `-3ltrlt-1`C. `rgt3orrlt1`D. none of these

Answer» Correct Answer - C
Let `a_(1),a_(2),a_(3)` be first three consecutive terms of G.P. with common ratio r. Then, `a_(2)=a_(1)randa_(3)=a_(1)r^(2)`.
Now,
`a_(3)gt4a_(2)-3a_(1)`
`rArr" "a_(1)r^(2)gt4a_(1)r-3a_(1)`
`rArr" "r^(2)gt4r-3`
`rArr" "r^(2)-4r+3gt 0rArr(r-1)(r-3)gt0rArrrlt1 or rgt3`


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