
Poushali G. answered 02/26/20
College Graduate Specializing in Math and Science tutoring
//Use the product rule for each part of the sum
d[6sec(t)]/dt = 6 * sec(t)tan(t) + 0 * sec(t) = 6sec(t)tan(t)
d[4tan(t)]/dt = 4 * sec2(t) + 0 * tan(t) = 4sec2(t)
//Then add them together and simplify
d[6sec(t) + 4tan(t)]/dt = 6sec(t)tan(t) + 4sec2(t) = 2sec(t) [3tan(t) + 2sec(t)]