The derivative of sec(x)\sec(x)sec(x) is:
sec(x)tan(x)\sec(x)\tan(x)sec(x)tan(x)
tan2(x)\tan^2(x)tan2(x)
sec2(x)\sec^2(x)sec2(x)
−sec(x)tan(x)-\sec(x)\tan(x)−sec(x)tan(x)