Determine the slope and y-intercept of the linear function represented by the following scenario:

An airplane starts it’s descent at an altitude (height) of 30,000 ft and descends at a rate of 2000 feet per minute.

1 answer

To determine the slope and y-intercept of the linear function representing the airplane's descent, we need to express the relationship between time and altitude in a linear form.

Let:

  • \( y \) represent the altitude of the airplane (in feet)
  • \( x \) represent the time (in minutes)

Given the information:

  • The airplane starts at an altitude of 30,000 feet. This gives us the y-intercept of the function.
  • The airplane descends at a rate of 2,000 feet per minute. This gives us the slope of the function.
  1. Y-Intercept: The y-intercept occurs when \( x = 0 \) (at the start of the descent). The altitude is 30,000 feet, so: \[ y\text{-intercept} = 30,000 \]

  2. Slope: The slope represents the rate of change of altitude with respect to time. Since the airplane is descending at 2,000 feet per minute, this is a negative slope: \[ \text{slope} = -2,000 \]

Combining these, the linear function can be written as: \[ y = -2000x + 30000 \]

Conclusion:

  • The slope is \(-2,000\).
  • The y-intercept is \(30,000\).