1.

Verify Rolles theorem for the function f(x)= x2 + 2x – 8, x ∈ [-4, 2]

Answer»

f (x) = x2 + 2x – 8 

1. f(x) being a polynomial function it is continuous on (-4, 2) 

2. Also f1 (x) = 2x + 2 hence derivable on (-4, 2) 

3. f(-4) = (-4)2 + 2(-4) - 8 = 0 

f(2) = 22 + 2(2) - 8 = 0 

∴ f(-4) = f(2)

∴ All three conditions of Rolle’s theorem are verified. 

f1(c) = 0 

f1 (c) = 2c + 2 ⇒ 0 = 2c + 2 

⇒ c = -1 ∈(-4, 2)



Discussion

No Comment Found

Related InterviewSolutions