Let S be the set of all points in ( - π , π) at which the function, f(x) = min sinx, cosx is not differentiable. Then S is a subset of which of the following?

Question

Let S be the set of all points in ( - π , π) at which the function, f(x) = min sinx, cosx is not differentiable. Then S is a subset of which of the following? (A)  - (3π/4) , (π/4) , (3π/4) , (π/4)  (B)  - (3π/4) , (π/2) , (π/2) , (3π/4)  (C)  - (π/2) , (π/4) , (π/4) , (π/2)  (D)  - (π/4) ,0, (π/4)

Tardigrade Admin · Accepted Answer

Correct answer is (a) - (3π/4) , (π/4) , (3π/4) , (π/4)

Q. Let S be the set of all points in $(- π, π)$ at which the function, f(x) = min {sinx, cosx} is not differentiable. Then S is a subset of which of the following?

${- \frac{3 π}{4}, \frac{π}{4}, \frac{3 π}{4}, \frac{π}{4}}$

${- \frac{3 π}{4}, \frac{π}{2}, \frac{π}{2}, \frac{3 π}{4}}$

${- \frac{π}{2}, \frac{π}{4}, \frac{π}{4}, \frac{π}{2}}$

${- \frac{π}{4}, 0, \frac{π}{4}}$

Correct answer is (a) ${- \frac{3 π}{4}, \frac{π}{4}, \frac{3 π}{4}, \frac{π}{4}}$

Q. Let S be the set of all points in (−π,π) at which the function, f(x) = min {sinx, cosx} is not differentiable. Then S is a subset of which of the following?

{−43π​,4π​,43π​,4π​}

{−43π​,2π​,2π​,43π​}

{−2π​,4π​,4π​,2π​}

{−4π​,0,4π​}