Eric Nicholas K's answer to Georgia Jansen's Secondary 4 A Maths Singapore question.

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Eric Nicholas K
Eric Nicholas K's answer
5997 answers (Tutor Details)
Done. This part can also be done by the second derivative test, but I prefer avoiding differentiation of the expression for dy/dx once more.