TEACHER-GUIDE-VERIFIED · TG-V9-031

4. For h(t) = -5t^2 + 30t + 2, find the time and height of the vertex.

Verified solution

Solution: t=-b/(2a)=-30/(-10)=3 s. h(3)=-45+90+2=47 m; vertex (3,47).

Source: Teacher Guide V9 · English V9. Match the numbers and wording in your printed question before using this solution.

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VIDEO HELP · TG-V9-031

Find the Maximum of a Flight Model (TG-V9-031)

Find the maximum of h(t) = -5t^2 + 30t + 2. The vertex occurs at 3 seconds with a height of 47 meters. Check using symmetry and completed-square form; the horizontal axis represents time, not flight distance.

Space Math Explorers · approved worked example · 1:41 · Watch on YouTube

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These pages reproduce verified solution steps for the registered V9 questions. It does not diagnose learning needs or replace instruction from a qualified teacher or tutor.