Q.

The number of points, at which the function f(x)=max{6x,2+3x2}+|x–1|cos|x2–14],x∈(–π,π), is not differentiable, is ________.          [2026]


Ans.

(3)

f(x)=max{6x,2+3x2}+|x–1|cos|x2–14]

Sharp corner at 3x2+2=6x

⇒ 3x2–6x+2=0 ⇒ x=6±36–246

⇒ x=3±33 ⇒ x=1±13∈(–π,π)

∴  2 points of non-differentiability

For |x–1|cos|x2–14|:x=1 is the point of non-differentiability.

∴  Hence, total 3 points of non-differentiability.