Question

Starting at 6:00 a.m., Lin spent a day hiking through a canyon. This graph shows her elevation (in meters) at some different times. Negative values of x represent times earlier than noon, and positive values of x represent times later than noon.

Please help me with this

Answer 1

Its 0

Explanation:

Answer 2

First, we know that the 0 in the horizontal axis corresponds to the noon.

Then:

a) Lin's elevation at noon in meters.

We need to see the elevation when x = 0.

This is the point that is just on top of the y-axis, we can see that when x = 0, we have y = 6.

Then at noon, her altitude was 6 meters.

b) At 8:00 am, her elevation was 2m

Remember that the x-component represents time, and x = 0 represents the noon.

8:00 am is 4 hours before noon, then 8:00am is represented with x = -4

and at this time her elevation is 2m, then y = 2.

This means that the point that represents this is (-4, 2)

c) At 4:00 pm Lin was at sea level (her elevation was 0m)

Same reasoning than before: x = 0 is the noon, then 4:00 pm is four hours after this, then 4:00 pm is represented with x = 4.

And here her altitude is 0m, then y = 0.

This point is written as (4, 0)

d) Here we can see that at 6:00 am her elevation was negative, and at 4:00pm her elevation is 0.

And we know that:

0 > negative numbers.

Then her altitude increased in this interval of time.