Fundamental theorem problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg49573] Fundamental theorem problem*From*: "Steven Jonak" <jonakst at gw.kirkwood.k12.mo.us>*Date*: Fri, 23 Jul 2004 06:01:42 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I input the command: D[Integrate[Sec[t],{t,1,x^4}],x] expecting to get 4x^3 Sec[x^4] but instead got a fairly complicated result that doesn't resemble what one would expect from the Fundamental Theorem of Calculus. What am I doing wrong? Help! S Jonak "Maintain an even strain."