A rugby player kicks a rugby ball 1 foot above the ground with an initial vertical velocity of 55 feet per second. The function h=-16t^2+55t+1 represents the height of the rugby ball after t seconds. Use a graphing calculator to estimate when the height of the rugby ball is 45 feet

The height of the rugby ball is 45 feet at t = 1.27s and t = 2.17s

Step-by-step explanation:

The height of the ball, in feet, after t seconds, is given by the following equation:

When the height of the rugby ball is 45 feet

This is t for which: h(t) = 45

So

Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

.

This polynomial has roots such that , given by the following formulas:

In this question:

So

The height of the rugby ball is 45 feet at t = 1.27s and t = 2.17s