請教如何解這一題數學---**Question Set 15-17**
**Introductory Text:**
坐標平面上, 設 Γ 為三次函數 f(x)=x³-9x²+15x-4 的函數圖形。根據上述, 試回答下列問題。
(On the coordinate plane, let Γ be the graph of the cubic function f(x)=x³-9x²+15x-4. Based on the above, answer the following questions.)
**Question 15:**
試問下列何者為 f(x) 的導函數? (單選題, 2 分)
(Which of the following is the derivative of f(x)? (Multiple choice, 2 points))
**Options for Question 15:**
(1) x²-9x+15
(2) 3x³-18x²+15x-4
(3) 3x³-18x²+15x
(4) 3x²-18x+15
(5) x²-18x+15
**Question 16:**
試說明 P(1,3) 為 Γ 上之一點, 並求 Γ 在 P 點的切線 L 的方程式。(非選擇題, 4 分)
(Explain that P(1,3) is a point on Γ, and find the equation of the tangent line L to Γ at point P. (Non-multiple choice, 4 points))
**Question 17:**
承 16, 試求 Γ 和 L 所圍成有界區域的面積。(非選擇題, 6 分)
(Following 16, find the area of the bounded region enclosed by Γ and L. (Non-multiple choice, 6 points))