2018-04-17

sin(a+b)=sinAcosB+sinBcosA

sin(a-b)=sinAcosB-sinBcosA

cos(a+b)=cosAcosB-sinAsinB

cos(a-b)=cosAcosB+sinAsinB

(tanA)2+1=(secA)2=1÷(cosA)2

(cotA)2+1=(cscA)2=1÷(sinA)2

1.y'+sin(x-y)=sin(x+y)

解:

1.∫secxdx=ln|secx+tanx|+c

2.∫cscxdx=ln|cscx-cotx|+c

3.∫I÷√a2+x2dx=ln|(x+√a2+x2)+c