Calculus problem

Question

Find  for y = 3cos(x) + sec(x).

Options:

1. -3sin(x) + sec(x)tan(x)
2. 3cos(x) - sec(x)tan(x)
3. 3sin(x) - sec²(x)
4. 3cos(x) - sec(x)

Answer 1

y = 3cos(x) + sec(x)

dy/dx = (3cos(x) + sec(x))'

= 3(cos(x))' + (sec(x))'

= 3(-sin(x)) + sec(x)tan(x)

= -3sin(x) + sec(x)tan(x)