Apabila cotα\cot\alphacotα =pq=\frac{p}{q}=qp, maka cosα=....\cos\alpha=....cosα=....
qp2+q2\frac{q}{\sqrt{p^2+q^2}}p2+q2q
pp2+q2\frac{p}{\sqrt{p^2+q^2}}p2+q2p
p2+q2q\frac{\sqrt{p^2+q^2}}{q}qp2+q2
p2+q2p+q\frac{\sqrt{p^2+q^2}}{p+q}p+qp2+q2
p2+q2p\frac{\sqrt{p^2+q^2}}{p}pp2+q2