Linear Programming — Test Answers

The Air Quality Index, or AQI, measures how polluted the air is in your city and assigns a number based on the quality of the air. Over 100 is “Unhealthy”. The following quadratic regression equation gives us an estimate of n, which is the number of days the AQI exceeded 100 a particular year. We will use this equation to estimate the number of days the AQI was over 100 in the year 1995. (Let t represent the number of years since 1990. Therefore, t = 0 corresponds to the year 1990. For the estimate of n, round to the nearest whole day.)

Solve the problem. A jump rope held stationary by two children, one at each end, hangs in a shape that can be modeled by the equation , where h is the height (in inches) above the ground and x is the distance (in inches) along the ground measured from the horizontal position of one end. How close to the ground is the lowest part of the rope?