+ysec2x=tan‌x⋅sec2x.....(i) Here, p=sec2x ⇒∫pdp=∫sec2x‌dx=tan‌x Multiplying Eq. (i) by IF, we get
etan‌x‌
dy
dx
+etan‌xysec2x=etan‌x⋅tan‌x⋅sec2x
Integrating both sides, we get yetan‌x=∫etan‌x‌tan‌x⋅sec2x‌dx On putting tan‌x=t, ‌sec2x‌dx=dt ∴‌‌yet=∫tet‌dt=et(t−1)+C ∴‌‌yetan‌x=tan‌x−1+Ce−tan‌x ‌ If ‌‌y(‌