y = 0.005x^2-0.801x+46.928

^ Using that model above, how di I determine the cost per km to the nearest tenth of a cent, at a speed of 70 km/h?

I think I use a graphing calculator for this, and since speed is the x value I probably have to insert in 70.

yes, just sub in x=70 and evaluate

(I got 15.358 or 15.4 to the nearest tenth )

To determine the cost per km to the nearest tenth of a cent at a speed of 70 km/h, you can follow these steps using the given model equation:

1. Substitute the value of speed (x) into the equation. In this case, substitute x = 70.

y = 0.005(70)^2 - 0.801(70) + 46.928

2. Simplify the equation by performing the necessary calculations:

y = 0.005(4900) - 56.07 + 46.928
= 24.5 - 56.07 + 46.928
= 15.358

3. The result, 15.358, represents the cost per km. However, we need to round it to the nearest tenth of a cent.

Rounding 15.358 to the nearest tenth of a cent gives us 15.4 cents per km.