2dy/dx = 4/(x+3)cos y

2dy/dx = 4/(x + 3)cos y /*dx 2dy = 4dx /(x + 3)cos y /* cos y 2cos y dy = 4dx/(x + 3) /:2 cos y dy = 2dx/(x + 3) ∫cos y dy = 2∫dx/(x + 3) sin y = 2ln|x + 3| sin y = ln|(x + 3)²| y = arcsin[ln|(x + 3)²|] + C