Why is it necessary to reverse the inequality symbol when multiplying both sides of an inequality by a negative number. Provide an example to support your explanation.

Question

Why is it necessary to reverse the inequality symbol when multiplying both sides of an inequality by a negative number.  Provide an example to support your explanation.

anonymous · Answer

hey

anonymous · Answer

Well, let's "provide an example" and see what is what. Shall we?

I think we can agree:

4 > 2

Now let's multiply both sides by a negative number, -1:

4(-1) > 2(-1)
-4 > -2 ??

You see that we run into a bit of a problem with this one. -4 is NOT greater than -2.

-4 < -2

See that we had to change the inequality? I'm no expert, but let me rig up a proof for you, just a second.

anonymous · Answer

iparke, i would be interested to see how you do on that link i gave you, you should check that out

anonymous · Answer

Haha, ok. What test should I do?

anonymous · Answer

i think they are both the same, just pdf or word format

anonymous · Answer

But Limits and Derivatives? I'm not too spectacular on my limits, I'd have to do another crash course. But I'll try it out.