# The mean position and one extreme position of the two different waves represented by $x=23 \sin(2t)$ and $x=5+23 \sin(2t)$ respectively are:

$\begin{array}{1 1}(a)\;46,0,28,-22 &(b)\;0,-23,5,-18 \\( c)\;23,0,28,46 &(d)\;0,23,5,-18 \end{array}$

$x=23 \sin (2t).$ Here the mean position given by $23 \sin (2 \times 0); 23 \sin (\pi); 23 \sin (2 \pi)$ etc are zero.
Hence zero is the right answer.
The extreme positions are $23 \sin (\large\frac{\pi}{2}),$$23 \sin (\large\frac{3 \pi}{2}),$$23 \sin (\large\frac{5 \pi}{2})$ which are $+23,-23$ etc.
In the correct answer $-23$ has been chosen.
Similarly for $5+ 23 \sin (\pi),5+23 \sin (2 \pi)$, & no on which is 5.
The corresponding extreme positions are $5+ 23 \sin \large\frac{\pi}{2};$$5+ 23 \sin \large\frac{3 \pi}{2};$$ 5+ 25 \sin \large\frac{5 \pi}{2}$ etc.
$\therefore$ right answer is $0,-23,5,-18$