📝 Properties Of Graphs

Q1. A company wants to locate a new warehouse so that the cost function \(C(x)=3x^{2}-12x+20\) is minimized. Which interval contains the x‑value where the cost is lowest?

💡 Difficulty: easy | ✅ Correct: B

Q2. A particle moves along a line with position \(s(t)=t^{3}-6t^{2}+9t\). During which time interval is its velocity increasing?

💡 Difficulty: medium | ✅ Correct: C

Q3. If a function's graph has a horizontal tangent at \(x=5\) and the function is decreasing on both sides of \(x=5\), what type of critical point is present?

💡 Difficulty: hard | ✅ Correct: C