The height, h, in feet, of a baseball t seconds after Tobin hit it with a baseball bat can be modeled by the equation:h(t)=−16t2+64t+4Which of the following equivalent expressions displays the value of the baseball's maximum height as a constant or coefficient?Choose 1 answer:(A) −16(t−2)2+68(B) −4t(4t−16)+4(C) −16(t2−4t−41)(D) −16(t2−4t)+4
Q. The height, h, in feet, of a baseball t seconds after Tobin hit it with a baseball bat can be modeled by the equation:h(t)=−16t2+64t+4Which of the following equivalent expressions displays the value of the baseball's maximum height as a constant or coefficient?Choose 1 answer:(A) −16(t−2)2+68(B) −4t(4t−16)+4(C) −16(t2−4t−41)(D) −16(t2−4t)+4
Problem Understanding: Understand the problem.We are given the quadratic equationh(t)=−16t2+64t+4, which models the height of a baseball t seconds after being hit. We need to find an equivalent expression that shows the maximum height of the baseball as a constant or coefficient.
Quadratic Equation Structure: Recognize the structure of the quadratic equation.The given equation is in the standard form of a quadratic equation, which is h(t)=at2+bt+c. The maximum height of the baseball will occur at the vertex of the parabola represented by this quadratic equation.
Finding Time of Maximum Height: Find the time at which the maximum height occurs.The time at which the maximum height occurs can be found using the formula t=−2ab, where a is the coefficient of t2 and b is the coefficient of t in the quadratic equation.For our equation, a=−16 and b=64, so t=−2×−1664=2 seconds.
Writing Equation in Vertex Form: Write the equation in vertex form.The vertex form of a quadratic equation is h(t)=a(t−h)2+k, where (h,k) is the vertex of the parabola. Since we know the time of the maximum height is 2 seconds, we can write the equation as h(t)=−16(t−2)2+k.
Calculating Maximum Height: Calculate the maximum height k. To find the value of k, we substitute t=2 into the original equation h(t)=−16t2+64t+4. h(2)=−16(2)2+64(2)+4=−64+128+4=68 feet. So, the maximum height k is 68 feet.
Final Vertex Form Equation: Write the final vertex form equation.Now that we have the value of k, we can write the final vertex form equation as h(t)=−16(t−2)2+68.
Matching with Given Choices: Match the final vertex form equation with the given choices.The final vertex form equation we found is h(t)=−16(t−2)2+68, which matches choice (A).
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