Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Graph:

  1. ${y\over|y|}={x\over|x|}$
  2. ${\lfloor x \rfloor \lfloor y \rfloor = 1}$

Determine if each graph represents a function of x and explain your answer.

I've never seen anything like the before and I'm not sure where to start.

share|improve this question
    
Try distinguishing cases: positive $y$, negative $y$, postive $x$, negative $x$ to get rid of the absolute values, and do a similar thing for the floor function. –  dreamer Mar 16 at 9:26
    
Don't tell me what to do. –  Mike Miller Mar 16 at 9:40

1 Answer 1

Hint:

  1. ${y\over|y|}={x\over|x|}$ \begin{cases} x \ge 0 \Rightarrow \frac{x}{|x|} = \frac{y}{|y|} = 1 \Rightarrow y \ge 0 \\ x \lt 0 \Rightarrow \frac{x}{|x|} = \frac{y}{|y|} = -1 \Rightarrow y \lt 0 \\ \end{cases} So ${y\over|y|}={x\over|x|}$ is a general way to refer to every functions whose graph is in the $I$ and $III$ quadrant of a Cartesian coordinate system.
  2. ${\lfloor x \rfloor \lfloor y \rfloor = 1} \Rightarrow \lfloor y \rfloor = \frac{1}{\lfloor x \rfloor} \ldots$
share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.