arctan(-5.671)=?

arctan(-5.671)=? arctan(-2)+arctan(-3)=? -arctan(-x)=-pai+arctan么? cos[arctan(1/2) - arctan(-2)]=? arctan(tanθ)=? arctan(sin x)=? arctan(tanx)=? arctan arctan(x/12)-arctan(x/10)-arctan(x/20)=-40最好能用matlab解.arctan(x/12)-arctan(x/10)-arctan(x/20)=-40/180*pi π－arctan(3/2)－arctan(2/3)=? arctan(A/2)+arctan(A/5)=30 为什么arctan(-x)=-arctanx 求导：y=arctan(lnx) y=arctan(lnx)求导~ 求证：arctan 1/2+arctan 1/5+arctan 1/8=π/4 arctan(y)=x+1, y=? y=arctan(1/x)求导 y=arctan（x/2）求导?