How can you write a trigonometric equation?

Question

Sublime Text

First to second

Answer 1

inc-dec value
https://github.com/rmaksim/Sublime-Text-2-Inc-Dec-Value

Answer 2

The Emmet extension has combinations in the key bindings settings for the following actions:

increment_number_by_1 / decrement_number_by_1 
increment_number_by_10 / decrement_number_by_10
increment_number_by_01 / decrement_number_by_01

Answer 3

Knowing that, sec^2(x) = 1/cos^2(x) ;
Open the brackets in the denominator on the right side of the equation:
cos^2(x) * (sin^2(x)/cos^2(x) + 5sin(x)/cos(x) + 6) =
sin^2(x) + 5sin(x)cos(x) + 6cos^2(x) =
-5sin^2(x) + 5sin(x)cos(x) + 6 .
The second equality from the fact that 6sin^2(x) + 6cos^2(x) = 6 .
Well, there is just a minus in front of the fraction in order to change the sign in the denominator.