Nilai dari 2sin(π2−α)cos(π2+α)=....2\sin\left(\frac{\pi}{2}-\alpha\right)\cos\left(\frac{\pi}{2}+\alpha\right)=....2sin(2π−α)cos(2π+α)=....
2sinα−12\sin\alpha-12sinα−1
sin2α\sin2\alphasin2α
1+sin2α1+\sin2\alpha1+sin2α
1−sin2α1-\sin2\alpha1−sin2α
−sin2α-\sin2\alpha−sin2α