Question 749968
It's a pure sine wave that is phase-shifted by {{{ pi/4 }}}
Make a chart with 3 headings:

x --------- x + pi/4 ---------- sin( x + pi/4 )
------------------------------------------
0 --------- 0 + pi/4 ---------- sin( pi/4 )
pi/4 ------ pi/4 + pi/4 -------- sin( pi/2 )
pi/2 ------ pi/2 + pi/4 -------- sin( ( 3*pi)/4 )

Keep on going and calculate the sines
You will end up with the {{{ pi/4 }}}
phase-shifted sine wave.
Here's a plot of both
{{{ sin( x ) }}} and {{{ sin( x + pi/4 ) }}}
{{{ graph( 600, 300, -10, 10, -1, 1, sin(x) , sin( x + pi/4 ) ) }}}