Home » algebra » CAT 1990 Question-4

CAT 1990 Question-4




Q.) The value of \frac { (1-{ d }^{ 3 }) }{ (1-d) } is
1) >1 if d>-1
2) >3 if d>1
3) >2 if 0 < d < 0.5

Solution: We know that

{ a }^{ 3 }-{ b }^{ 3 }=(a-b)({ a }^{ 2 }+ab+{ b }^{ 2 })

X = \frac { (1-{ d }^{ 3 }) }{ (1-d) } = \frac { (1-d)(1+d+{ d }^{ 2 }) }{ (1-d) } =(1+d+{ d }^{ 2 }) Here , if d>1 , X >3

Hence , Option(2)





1 Comment

Leave a comment