Math Is Fun Forum

paulb203

Member

Registered: 2023-02-24

Posts: 323

Inequalities on Graphs

I came across the following inequality in this context;

x ≤ 6-2y

My instinct was to rearrange it to have y on the left hand side thus;

y ≤ -(1/2x) +3

Should I have bothered?

I guess I'm used to seeing it that way.

---

Prioritise. Persevere. No pain, no gain.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,627

Re: Inequalities on Graphs

I would do the same.  To get the boundary line it helps to have it in the form y = mx + c.  Then you just have to decide which side of the line satisfies the inequality.

The 'lazy' way to do that is to pick a point on one side and see if it fits the inequality.  As any point will do, choose one that makes the calculations easy.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

paulb203

Member

Registered: 2023-02-24

Posts: 323

Re: Inequalities on Graphs

Thanks, Bob.

---

Prioritise. Persevere. No pain, no gain.