# functions

• Aug 7th 2008, 02:26 AM
stewpot
functions
Hi, I've been asked to model the motion of a car, t = seconds (from 0 to 10) and y = meters (0 to 100). For the first 10 seconds the motion can be described as y=100-1.5t^2. When plotted I get a negative parabola, the vertex at y=-50. When plotting the nDeriv I also get a negative result. Is this right or am I entering the function incorrectly?
• Aug 7th 2008, 03:43 AM
mr fantastic
Quote:

Originally Posted by stewpot
Hi, I've been asked to model the motion of a car, t = seconds (from 0 to 10) and y = meters (0 to 100). For the first 10 seconds the motion can be described as y=100-1.5t^2. When plotted I get a negative parabola, the vertex at y=-50. When plotting the nDeriv I also get a negative result. Is this right or am I entering the function incorrectly?

The graph of \$\displaystyle y = -1.5 t^2 + 100\$ is a negative parabola that has a maximum turning point at (0, 100). Over the domain you give, it starts at the point (0, 100) and ends at the point (10, -50).

So the car travels in a straight line from y = 100 to y = -50. It travels a distance of 150 meters.