For $a,b\in\Bbb R$ prove $|a-b|<E$ iff $a-E<b<a+E$.
I am unsure how to start this proof. I think it might have something to do with the reverse triangle inequality but I am stuck.
For $a,b\in\Bbb R$ prove $|a-b|<E$ iff $a-E<b<a+E$.
I am unsure how to start this proof. I think it might have something to do with the reverse triangle inequality but I am stuck.