How do you move floors and ceilings in discrete math?

In summary, floors and ceilings in discrete math are defined as the largest integer less than or equal to a given number and the smallest integer greater than or equal to a given number, respectively. They can be used to solve equations involving absolute values and can be moved in equations using their properties or algebraic manipulations. Floors and ceilings are also commonly used in proofs to show that a value is an integer or to simplify expressions. Important properties to remember include floor(x) + ceiling(x) = x + 1 and floor(-x) = -ceiling(x) for all real numbers x, and the fact that they are discontinuous functions.
  • #1
iScience
466
5
The title more accurately should have been "How do you cancel floors and ceilings in discrete functions"

For instance,

##\frac{log{\frac{3x}{-6(z)}}}{8t} < 1##

If I wanted to get rid of the log, I'd just raise the expression by base 10.

##\frac{(\frac{3x}{-6(z)})}{10^{8t}} < 10^1##

But what happens if there's a roof for discrete functions?

##\frac{\lceil{log \frac{10x}{4y}}\rceil}{8z} < 1##

How do I handle this?

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EDIT NOTICE: the expressions above have been fixed into its their proper inequalities
 
Last edited:
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  • #2
iScience said:
For instance,

##\frac{log{\frac{3x}{-6(z)}}}{8t}##

If I wanted to get rid of the log, I'd just raise the expression by base 10.

##\frac{(\frac{3x}{-6(z)})}{10^{8t}}##
i rather hope you would not do that, since it is wrong.
 
  • #3
oops, sorry, here's the other side

##\frac{log(stuff)}{8t} < 1 ##

##\frac{stuff}{10^{8t}} < 10 ##
 
  • #4
iScience said:
oops, sorry, here's the other side

##\frac{log(stuff)}{8t} < 1 ##

##\frac{stuff}{10^{8t}} < 10 ##
Still wrong.

##\frac{\log(stuff)}{8t} < 1 ##
##\log(stuff)<8t##
##stuff<10^{8t}##
For your ceil question, it might help if you state the entire problem.
 
  • #5
iScience said:
But what happens if there's a roof for discrete functions?

##\frac{\lceil{log \frac{10x}{4y}}\rceil}{8z} < 1##
Assuming z>0, z>0 leads to a very similar case:
##\lceil{stuff\rceil} < 8z##
What is the largest value of stuff that satisfies the inequality? Once you found that, you can continue with the usual approaches.
 

FAQ: How do you move floors and ceilings in discrete math?

How do you define a floor or ceiling in discrete math?

In discrete math, a floor is defined as the largest integer less than or equal to a given number. A ceiling, on the other hand, is defined as the smallest integer greater than or equal to a given number.

Can floors and ceilings be used to solve equations?

Yes, floors and ceilings can be used to solve equations in discrete math. They are particularly useful in solving equations involving absolute values.

How do you move a floor or ceiling in an equation?

To move a floor or ceiling in an equation, you can use the properties of floors and ceilings, such as the fact that floor(x) is always less than or equal to x, and ceiling(x) is always greater than or equal to x. You can also use algebraic manipulations to simplify the equation and then apply the floor or ceiling function.

Can floors and ceilings be used in proofs?

Yes, floors and ceilings can be used in proofs in discrete math. They are commonly used to show that a certain value is an integer or to help simplify expressions. They can also be used to prove inequalities.

Are there any important properties of floors and ceilings to remember?

Yes, there are several important properties of floors and ceilings to remember. For example, floor(x) + ceiling(x) = x + 1, and floor(-x) = -ceiling(x) for all real numbers x. It is also important to remember that floors and ceilings are discontinuous functions, meaning that small changes in the input can result in large changes in the output.

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