# How to find second and third derivative using ForwardDiff

How do I find the second and third derivative using ForwardDiff

I can find the first derivative 14.0 at x = 1.0 using the following

``````using ForwardDiff

f(x) = 7*x^2
result = ForwardDiff.derivative(f,1.0)
println(  "first derivative is ",result )
``````
``````ForwardDiff.derivative(x -> ForwardDiff.derivative(f, x), 1.0)
``````
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It works thank you.

``````using ForwardDiff

f(x) = 7*x^3
result = ForwardDiff.derivative(f,1.0)
println(  "first derivative is ",result )
result2 = ForwardDiff.derivative(x -> ForwardDiff.derivative(f, x), 1.0)
println(  "second derivative is ",result2 )
``````

Output

``````Starting Julia...
_
_       _ _(_)_     |  Documentation: https://docs.julialang.org
(_)     | (_) (_)    |
_ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _  |  |
| | |_| | | | (_| |  |  Version 1.0.3 (2018-12-18)
_/ |\__ _|_|_|\__ _|  |  Official https://julialang.org/ release
|__/                   |

first derivative is 21.0
second derivative is 42.0
``````
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