Question:

<div class="solution"><p>h(t)=t³-6t²+9t-3 peaks at t=1. g(x)=h(x) for x∈[0,1], then h(1)=1 constant for x∈[1,3]. At x=3: g'(3⁻)=0, g'(3⁺)=-1. Non-diff at x=3 only. <strong>Answer: 1</strong></p><div class="key-concept"><strong>Key Concept:</strong> Running max: creates flat region; non-diff at join point with next piece</div></div>