Inverse trigonometric function can not be narrowly understood as the inverse function of trigonometric function, but a multi-valued function. It is the general name of the functions of arcsine x, arccosine, arctangent, arctangent x and arctangent x, which respectively represent the angles at which sine, cosine, tangent and cotangent are x.

Other formulas of inverse trigonometric function

cos(arcsinx)=√( 1-x^2)

Arcsine (-x)=- Arcsine

arccos(-x)=π-arccosx

Arctangent (-x)=- arctangent

arccot(-x)=π-arccotx

arcs inx+arc cosx =π/2 = arctanx+arccotx

sin(arc sinx)= cos(arc cosx)= tan(arc tanx)= cot(arc cotx)= x

When x∈[-π/2, π/2] has sine (sinx) = X.

x∈[0，π]，arccos(cosx)=x

x∈(-π/2，π/2)，arctan(tanx)=x

x∈(0，π)，arccot(cotx)=x

X>0, arctanx=π/2-arctan 1/x, and arccotx is similar.

If (arctanx+arctany)∈(-π/2, π/2), then arctanx+arctany = arctan ((x+y)/(1-xy)).