cosx=1/p dng π/2

cosx = 1/p (samping/miring)

mencari sisi depan
depan² + samping² = miring²
depan² = miring² - samping²
            = p² - 1²
depan = [tex] \sqrt{p^2-1} [/tex]

sinx = depan/miring = [tex] \frac{\sqrt{p^2-1} }{p} [/tex]
tanx = depan/samping = [tex] \sqrt{p^2-1} [/tex]
karena mempunyai batas π/2<x<π maka tanx bernilai negatif (-)

sinx-tanx = [tex] \frac{\sqrt{p^2-1} }{p} - (- \sqrt{p^2-1}) [/tex]
               = [tex] \frac{\sqrt{p^2-1} }{p} + \sqrt{p^2-1} [/tex]
               = [tex] \frac{(1+p)\sqrt{p^2-1} }{p} [/tex]