Mark the correct alternative in the following:
The value of c in Rolle’s theorem for the function f(x) = x3 – 3x in the interval is
f(x) = x3 – 3x
The above mentioned polynomial function is continuous and derivable in R.
the function is continous on [0,
] and derivable on [0,
].
Differentiating the function with respect to x,
f(x) = x3 – 3x
f’(x) = 3x2 – 3
f’(c) = 3c2 – 3
f’(c) = 0
3c2 – 3 = 0
c2 – 1 = 0
c2 = 1
c = ± 1
Hence, c = 1 Є [0, ], as per the condition of Rolle’s Theorem.
The required value is c = 3.
Hence, Option (A) is the answer.