SOLUTION: Can you help me solve this expression in order to find out where it is true?
{{{ cos(-7pi/2) }}} = {{{ cos(pi + pi/2) }}}
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-> SOLUTION: Can you help me solve this expression in order to find out where it is true?
{{{ cos(-7pi/2) }}} = {{{ cos(pi + pi/2) }}}
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You can put this solution on YOUR website! cos (-7pi/2)=cos(-pi/2)=0, because one can add 2pi multiples without changing the location to get -5pi/2, -3pi/2, and -pi/2
Therefore, cos (pi+pi/2)=0. That is cos (3 pi/2), where it occurs. 270 degrees. ANSWER
It is also cos (pi)*cos(pi/2)-sin (pi)*sin (pi/2)=0
The first is -1*0-0(1)=0, so it is an identity.
