If x=Acos4t+Bsin4t, then d2xdt2 is equal to:
-16x
16x
x
-x
Explanation for the correct option.
x=Acos4t+Bsin4t⇒dxdt=-4Asin4t+4Bcos4t⇒d2xdt2=-16Acos4t-16Bsin4t=-16Acos4t+Bsin4t=-16x
Hence, option A is correct.