Another Method to Find the Derivative of Sin

1　 IntroductionIt is very important to find thederivative of sine in mathematics.For eachderivative of trigonometric functions isbegin with sine.The sketch of its proof istransforming two subtracted sine functionsinto the form of multiplication1 ] 2 ] 3 ] 4] 5] 6] .But this method appears the form offraction,so it is difficult for the beginnersand the self - learners to understand theincrement of the sine functionΔy1 ]Δy =sin(x +Δx) - sinx=2 cos(x +Δx2 ) sinΔx2 .In this paper,we …