為了不引起混亂,先將arc cosx寫成ARCcosx
首先要知道ARCcosx的導(dǎo)數(shù)dy/dx=-1/√(1-x²)
y=ARCcosx/√(1-x²)
dy/dx=1/[√(1-x²)]²*{√(1-x²)*[-1/√(1-x²)]-ARCcosx*1/[2√(1-x²)]*(-2x)}
=1/(1-x²)*[-1+xARCcosx/√(1-x²)]
=1/(1-x²)*[-√(1-x²)+xARCcosx]/√(1-x²)
=[xARCcosx-√(1-x²)]/[(1-x²)^(3/2)]