How do you differentiate g(t)=4sect+tant?

1 Answer
May 2, 2017

g'(t)=4sect tant+sec^2t=sect(4tant+sect)

Explanation:

The following trigonometric derivatives are very useful:

  • d/dtsect=sect tant
  • d/dttant=sec^2t

Thus,

g'(t)=4sect tant+sec^2t=sect(4tant+sect)


We can derive both of these derivatives:

sect=(cost)^-1

d/dxsect=-(cost)^-2d/dtcost=(-1)/cos^2t(-sint)

=sect tant

And:

tant=sint/cost

d/dttant=((d/dtsint)cost-sint(d/dtcost))/cos^2t=(cos^2t+sin^2t)/cos^2t

=sec^2t