absolute value question

[smallsorrow]

Is lx-yl > lxl + lyl ?

1) y<x
2)xy<0

how do i treat the values here - as positive?
Thank you for an explanation..

[maihuna]

do u mean lx-yl > lxl - lyl ?

[smallsorrow]

yes, i do...

[scoobydooby]

am getting B.

is lx-yl < lx-0l - ly-0l ?

1) y<x

case 1: let x and y both be positive.
-------0----y----x

we get lx-yl = lx-0l - ly-0l . No

case 2: let x be positive and y be negative.
-----y----0------x

we get lx-yl = lx-0l + ly-0l >lx-0l - ly-0l
=>lx-yl >lx-0l - ly-0l . Yes

not sufficient.


stmnt 2) xy<0
=> x and y are of opposite signs.

case 1: x>y
---y----0------x

we get lx-yl = lx-0l + ly-0l >|x|-|y|
=>lx-yl >lx-0l - ly-0l . Yes


case 2: x<y
---x----0-----y

we get lx-yl = lx-0l + ly-0l >|x|-|y|
=>lx-yl >lx-0l - ly-0l . Yes
sufficient.

hence, B

[vittalgmat]

B for me as well.

solved by plugging in numbers.

one takeaway from this.

whenever u see something like
xy < 0, immediately translate to the following
One of them is +ve and the other is -ve.
ie. x: +ve, y: -ve Or x: -ve, y: +ve

similarly
xy > 0
both x and y are +ve.