JEE Main20204 Sep 2020Evening ShiftMathematicsFunctionsActual
The minimum value of 2 sin x + 2 cos x is :
Options
- A2 - 1 + 1 2
- B2 - 1 + 2
- C2 1 - 2
- D2 1 - 1 2
Correct answer
D. 2 1 - 1 2
Step-by-step solution
Using A . M ≥ G . M . 2 sinx + 2 cosx 2 ≥ 2 sinx · 2 cosx ⇒ 2 sinx + 2 cosx ≥ 2 1 + sinx + cosx 2 Now - 2 ≤ sinx + cosx ≤ 2 So minimum value of 2 sinx + 2 cosx = 2 1 + - 2 2 = 2 1 - 1 2