NTA Abhyas JEE Main2020MathematicsFunctionsPractice
sin a x + cos a x and | sin x | + | cos x | are periodic with the same fundamental period, if a equals to
Options
- A0
- B1
- C2
- D4
Correct answer
D. 4
Step-by-step solution
s i n a x + cos a x = 2 sin a x + π 4 So, fundamental period = 2 π a Let, T be the fundamental period of sin x + cos x So sin ( x + T ) + cos ( x + T ) =   sin x + cos x . Squaring both sides, we get, 1 + s i n ( 2 x + 2 T ) = 1 + sin 2 x Therefore, the fundamental period of s i n x + c o s x is π 2 Hence, 2 π a = π 2 ⇒ a = 4