Two wave are represented by equation `y_(1) = a sin omega t` and `y_(2) = a cos omega t` the first wave :-

Options

A. leads the second by `pi`
B. lags the second by `pi`
C. leads the second by `(pi)/(2)`
D. lags the second by `(pi)/(2)`

Answer

D

Explanation

`y_(1) = a sin omega t`
`y_(2) = a cos omega t = a sin(omega t + pi//2)`
`y_(1)` lags `y_(2)` behind by phase `(pi)/(2)`