Çözüldü Projectile - Parabola - Derivative

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https://parnellchs.weebly.com/uploads/2/3/1/3/23136554/act_practice_test_math_1.pdf
(Page 8, Question 57, Answers: Page 9)

I. is affected because c directly gives the height at t = 0.
II. is affected because h'(t) = -2a·t + b = 0 ⇒ t = b / (2a) and for another c1 ≠ c,
New height = h[ b / (2a) ] = -a·[ b / (2a) ]^2 + b·[ b / (2a) ] + c1 ≠
Old height = h[ b / (2a) ] = -a·[ b / (2a) ]^2 + b·[ b / (2a) ] + c ⇒ c1 ≠ c
III. is affected because for another c1 ≠ c and 0 = -a·t^2 + b·t + c1 has two different t intercepts (roots) depending on c1.
K (I, II, and III) is correct.