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A. find an equation for f(t) B. explain how you can use the graph's t-intercept to check the reasonableness of your equation.

A. find an equation for f(t) B. explain how you can use the graph's t-intercept to-example-1

1 Answer

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the form of a parabola has the form


f(t)=at^2+bt+c

when t=0


f(0)=c

usinc the graphic when t = 0 the value on the y axis is 45


c=45

now using the formula for the vertex:


\begin{gathered} \text{vertex}=(h,k) \\ h=(-(b)/(2a));k=f(-(b)/(2a)) \\ \end{gathered}

since h=0


0=-(b)/(2a)\rightarrow b=0

the only possible way for this to be 0 is if the numerator is equal to 0, reason why b is 0

now using the point given, we find a


\begin{gathered} y=at^2+c \\ 29=a+45 \\ 29-45=a \\ a=-16 \end{gathered}

re write the equation


f(t)=-16x^2+45

there is not h, inside the parentheses beacuse h=0

Does the equation makes sense?

Yes, because the number accompanying the x^2 the parabola is upside-down, also the vertex its on (0,45) menaing the parabola moved 45 units up.

Also since the hammer is dropping the y should become less ultil it gets to the floor.

User Nurdin
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