Don't wait for luck

Geometry Level 2

Find area enclosed by 2 x + 3 y 6 2|x| + 3|y| \leq 6 in square units.


Details And Assumptions:

  • a |a| is the distance of " a a " from origin. For example , 9 = 9 |9| = 9 and 9 = 9 |-9| = 9 .


The answer is 12.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Peter Michael
Dec 22, 2015

Consider the boundaries of each dimension by making one component(the x and then the y) zero. This implies that x 2 |x|\leq2 and y 3 |y|\leq3 . Since this space is bounded linearly we should realize that we have a rhombus. The way to calculate the area for such a shape is by multiplying the length of the diagonals and then dividing that result by two. The diagonals are clearly of length 4 and 3 which can be surmised from the two inequalities derived earlier and making note that x can be both positive and negative.

Moderator note:

Why does "space is bounded linearly" imply that we have a rhombus?

While I agree that we have a rhombus, there should be a better explanation of why.

Good observation of using the diagonals to find the area, instead of trying to hunt down the side lengths and angle inbetween.

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...