See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

If f(x) = 0 equality holds. If  f x 0   , we apply mean value theorem taking  x f x   and x as end pts of interval       f x f x f x f c f x             f x f x f x f c f x 0             f x f x f x 0      only possibility is f(x) = 0.