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MathsMediumMCQ2019 · 12 Jan Shift 1

Q80.Let S be the set of all points in (−π, π) at which the function, f(x) = min{sin x, cos x} is not differentiable. Then S is a subset of which of the following? (1) {−3π4 , −π2 , π2 , 3π4 } (2) {−3π4 , −π4 , 3π4 , π4 } (3) {−π4 , 0, π4 } (4) {−π2 , −π4 , π4 , π2 }

What This Question Tests

This question assesses understanding of differentiability, particularly for functions defined as the minimum of two other functions. The points of non-differentiability occur where the two functions are equal and their derivatives are different.

Concepts Tested

Differentiability of min/max functionsTrigonometric equations

Formulas Used

f(x) = min{g(x), h(x)} is not differentiable where g(x) = h(x) and g'(x) != h'(x)

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