Antoine stands on a balcony and throws a ball to his dog, who is at ground level. The ball's height (in meters above the ground), x seconds after Antoine threw it, is modeled by:h(x)=−2x2+4x+16How many seconds after being thrown will the ball hit the ground?seconds
Q. Antoine stands on a balcony and throws a ball to his dog, who is at ground level. The ball's height (in meters above the ground), x seconds after Antoine threw it, is modeled by:h(x)=−2x2+4x+16How many seconds after being thrown will the ball hit the ground?seconds
Write height equation: Write down the equation that models the height of the ball.The equation given is h(x)=−2x2+4x+16, where h(x) represents the height of the ball x seconds after being thrown.
Set equation equal to zero: Set the height equation equal to zero to find when the ball will hit the ground.To find when the ball hits the ground, we need to solve for x when h(x)=0.0=−2x2+4x+16
Factor quadratic equation: Factor the quadratic equation to solve for x.We can factor the quadratic equation by finding two numbers that multiply to −32 (−2×16) and add to 4 (the coefficient of x). However, this quadratic does not factor easily, so we will use the quadratic formula instead.
Apply quadratic formula: Apply the quadratic formula to find the values of x.The quadratic formula is x=2a−b±b2−4ac, where a=−2, b=4, and c=16.x=2(−2)−4±42−4(−2)(16)
Calculate values of x: Calculate the values of x using the quadratic formula.x=−4−4±144x=−4−4±12
Solve for possible values of x: Solve for the two possible values of x.x=(−4)(−4+12)=(−4)8=−2x=(−4)(−4−12)=(−4)−16=4Since time cannot be negative, we discard the negative value.
Conclude time of ball hitting ground: Conclude the time when the ball will hit the ground.The ball will hit the ground after 4 seconds.
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