Respuesta :
The soccer ball returns to the ground after 4 seconds, got from solving the quadratic function y = -16t² + 64t.
What is a polynomial function?
A polynomial function is a relation where a dependent variable is equal to a polynomial expression. A polynomial expression is an expression including numbers and variables, where variables are raised to non-negative powers.
The general form of a polynomial expression is:
a₀ + a₁x + a₂x² + a₃x³ + ... + aₙxⁿ.
The highest power to a variable is the degree of the polynomial expression.
When degree = 2, the function is a quadratic function.
When degree = 1, the function is a linear function.
How do we solve the given question?
We are given a quadratic function representing the height of the ball after a goalie kicks it. The function is y = −16t² + 64t, where y is the height in feet of the ball at time t seconds.
We are asked how long it takes for the soccer ball to return to the ground.
To calculate the time for the ball to return to the ground, we take height y = 0.
Our equation therefore is,
0 = -16t² + 64t
or, 16t² - 64t = 0
or, t² - 4t = 0
or, t(t-4) = 0
∴ Either, t = 0; Or, t-4 = 0 ⇒ t = 4.
∴ The height of the ball is 0 when time t is 0 and 4. Time 0 is before the goalie kicked the ball, so we take t = 4 seconds.
∴ The ball takes 4 seconds to return to the ground.
Learn more about Quadratic Functions at
https://brainly.com/question/1214333
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