Question 1007632
{{{cos(theta+pi/2) = cos(theta)cos(pi/2) - sin(theta)sin(pi/2)}}}


{{{cos(theta+pi/2) = cos(theta)*0 - sin(theta)*1}}}


{{{cos(theta+pi/2) = 0 - sin(theta)}}}


{{{cos(theta+pi/2) = -sin(theta)}}}


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{{{cos(theta-pi/2) = cos(theta)cos(pi/2) + sin(theta)sin(pi/2)}}}


{{{cos(theta-pi/2) = cos(theta)*0 + sin(theta)*1}}}


{{{cos(theta-pi/2) = 0 + sin(theta)}}}


{{{cos(theta-pi/2) = sin(theta)}}}


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{{{cos(theta+pi/2) - cos(theta-pi/2) = -sin(theta)-sin(theta)}}}


{{{cos(theta+pi/2) - cos(theta-pi/2) = -2sin(theta)}}} <---- Final Answer