Why should you only consider positive x values and y values on your graph?

If you are talking about length of an item it can only be positive.

If you talk about time it can only be positive.

If you talk about distance traveled it can  only be positive.

Things that cannot be negative in the real world, cannot be negative on the graph.

options a,b,c are the right answer.

step-by-step explanation:

a linear parent function is always represented as y = x

if we write this function in the form of y=mx+c

⇒

or  

now if we plot a graph we will find these characteristics:

1) y intercept of the graph is zero so its a straight line passing through origin.

2) as we can see in both the forms of function written, values of x and y may be either positive or negative for the positive slope means points on the graph are either in first quadrant or in third one.

3) it's slope is one.