QN's answer to QN's Junior College 1 H1 Maths Singapore question.

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QN
Qn's answer
19 answers (A Helpful Person)
t=9/4 and t=6
When 2nd derivative > 0
J
J
4 years ago
It should be -28/3 (you forgot the -)
J
J
4 years ago
You should be getting d²θ/dt² = -25/12 for t = 9/4 and d²θ/dt² = 0 for t = 6
QN
QN
4 years ago
Oh haha
So when I get zero when t=6, do I say
d^2θ/dt^2 = 0 (Invalid)
And proceed to do first derivative?
J
J
4 years ago
You can write (inconclusive)

Then do first derivative test.
QN
QN
4 years ago
Ok thanks!