Arun
Last Activity: 6 Years ago
Dear student
dwr to x
y'= Sec^2 x + Sec x tan x = y Sec x
y” = y sec x tan x + y'sec x
= sec x ( ytanx + y')
= sec x ( tan^2x + sec x tan x + sec x tan x + sec^2 x)
= sec x ( sec x + tan x )^2
= (1/cos x)( 1+ Sin x/Cosx )^2
= (1+Sin x)^2/ Cos^3 x
= (1+Sin x)^2. (1-Sin x)^2/Cos^3 x (1-Sin x)^2
= Cos^4 x / Cos^3 x (1-Sin x)^2
= Cos x / (1-Sin x)^2.