secx的导数是什么

（secx）

= (1 / cosx)

= [1cosx - (cosx)] / cos^2 x

= sinx / cos^2 x

= secxtanx

商的导数公式：

(u / v)' = [u * v^(-1)]'

= u' * [v^(-1)] + [v^(-1)]' * u

= u' * [v^(-1)] + (-1)v^(-2)*v' * u

= u' / v - u*v' / (v^2)

通分，易得

(u / v) = (u'v - uv') / v

常用导数公式：

1. c' = 0

2. x^m = mx^(m - 1)

3. sinx' = cosx，cosx' = -sinx，tanx' = sec^2x

4. a^x' = a^xlna，e^x' = e^x

5. lnx' = 1 / x，log(a,x)' = 1 / (xlna)

6. (f ± g)' = f' ± g'

7. (fg)' = f'g + fg'