Find the nth derivative of
- find the nth derivative of e^ax
- find the nth derivative of log(ax+b)
- find the nth derivative of cos(ax+b)
- find the nth derivative of sin(ax+b)
- find the nth derivative of e^x log x
- find the nth derivative of 1/x^2+a^2
- find the nth derivative of e^ax cos(bx+c)
- find the nth derivative of e^ax sin(bx+c)
- find the nth derivative of tan inverse 2x/1-x^2
- find the nth derivative of cosx cos2x cos3x
