Question 823644
The angle whose sin is {{{ .25 }}} is {{{ 14.478 }}} degrees
{{{ 360 - 14.478 = 345.522 }}} which places it in the 4th quadrant
{{{ s = 345.522 }}}
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The angle whose cosine is {{{ 4/5 }}} is {{{ 36.870 }}} degrees
{{{ 180 - 36.870 = 143.130 }}} which places it in the 2nd quadrant
{{{ t = 143.130 }}}
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{{{ sin( s + t ) = sin( 345.522 + 143.130 ) }}}
{{{ sin( s + t ) = sin( 488.652 ) }}}
{{{ sin( s + t ) = sin( 3*180 - 488.652 ) }}}
( this shows that the angle ends up in the 2nd quadrant )
{{{ sin( s + t ) = sin( 540 - 488.652 ) }}}
{{{ sin( s + t ) = sin( 51.348 ) }}}
{{{ sin( 51.348 ) = .781 }}}
( note that the sin is positive in the 2nd quadrant