Question

Statement I: Sine and cosine functions are periodic functions .
Statement II: Sinusoidal functions repeat its values after a definite interval of time.

• A. If both statement $I$ and statement II are true and statement II is the correct explanation of statement $I$.
• B. If both statement $I$ and statement II are true but statement II is not the correct explanation of statement $I$.
• C. If statement $I$ is true but statement II is false.
• D. If both statement $I$ and statement II are false.

Answer 1

Answer: (A)

A function $f(t)$ is said to be periodic of time period $T$ if $f(t+T)=f(t)$
All sine or cosine functions are periodic. Thus, $y=A$
$\sin \omega t$ or $A\cos \omega t$ is periodic of time period $T=\frac{2\pi }{\omega }$.