Answer:
The x-intercept will tell you how many seconds have passed before Dante lost sight of the rock.
Step-by-step explanation:
The problem specifies that the function d(s) will model the depth in feet of a rock that Dante dropped into a lake s seconds after he lost sight of the rock.
In this case we are using an s instead of the x, so the x-intercept will represent a given time. We can find the x-intercept by setting the function equal to zero, like this:
-5s-15=0
when solving for s we get:
s=-3
This means that Dante dropped the ball into a lake 3 seconds before he lost sight of the rock. This is what the negative stands for, some time in the past.
So the x-intercept tells us the time it took for Dante to lost sight of the rock.