已知f(u)可导,y=f{ln[x+√(a+x^2)]},求y'

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/05 20:33:39
已知f(u)可导,y=f{ln[x+√(a+x^2)]},求y'

已知f(u)可导,y=f{ln[x+√(a+x^2)]},求y'
已知f(u)可导,y=f{ln[x+√(a+x^2)]},求y'

已知f(u)可导,y=f{ln[x+√(a+x^2)]},求y'
y'=f'(ln(x+√(a+x²)))·ln(x+√(a+x²))‘
=f'(ln(x+√(a+x²)))·1/(x+√(a+x²))· (x+√(a+x²))‘
=f'(ln(x+√(a+x²)))·1/(x+√(a+x²))· (1+x/√(a+x²))
=f'(ln(x+√(a+x²)))·1/(x+√(a+x²))· (x+√(a+x²))/√(a+x²))
=f'(ln(x+√(a+x²)))·1/√(a+x²))

y'=f'(u)*u'x
=f'(u)*ln[x+√(a+x^2)]'
=f'(u)*[x+√(a+x^2)]'/[x+√(a+x^2)]
=f'(u)*[1+x/√(a+x^2)]/[x+√(a+x^2)]
=f'(u)/√(a+x^2)