NCERT Class 12 · Ch 6 Exercise 6.2 · Q5
NCERT Class 12 Maths · Chapter 6 Applications Of Derivatives · Exercise 6.2 Question 5
Find intervals of increase and decrease for f(x)=\(2 x^{3} - 3 x^{2} - 36 x + 7\).
💡 Concept Hints
- Identify the domain and the inner and outer functions, or the relevant one-sided limits.
- Apply the appropriate differentiation or limit rule, keep all chain factors, and check exceptional points.
✅ Step-by-Step Solution
Final Answer: Increasing on (−∞,−2) and (3,∞); decreasing on (−2,3).
- f′=6x²−6x−36=6(x+2)(x−3).
- A sign chart is +,−,+ across −2 and 3, giving increase, decrease, increase.
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