Question 546933
The amplitude of the sinusoid has to vary from 
6 ft above ground to 56 ft above ground.
Normally a sinusoid varies from +A to -A
where A  is the amplitude, which is 25
So, if I add a constant B, I get
B + 25 = 56 and
B - 25 = 6
2B = 62
B = 31
Now I get
{{{ 31 + 25*cos( (t*pi)/10 - pi/2) }}}
At  t=0
{{{ 31 + 25*sin( (0*pi)/10 - pi/2) }}}
{{{ 31 + 25*sin( (-pi/2)) }}}
{{{ 31 - 25 = 6 }}}
At t = 10 sec, I have
{{{ 31 + 25*sin( (10*pi)/10 - pi/2) }}}
{{{ 31 + 25*sin( (pi/2)) }}}
{{{ 31 + 25 = 56 }}}
At t = 20
{{{ 31 + 25*sin( (20*pi)/10 - pi/2) }}}
{{{ 31 + 25*sin( 2*pi - pi/2 ) }}}
{{{ 31 + 25*sin( (3*pi)/2) }}}
{{{ 31 - 25 = 6 }}}
This seems to work. The equation is
{{{ 31 + 25*sin( t*pi/10 - pi/2 ) }}}
The plot is
{{{ graph( 400, 400, -5, 50, -5, 60, 31 + 25*sin( (pi/10)*x - pi/2 ) ) }}}