1.(x^2+1)dx=(3y^2-2)dy 2.cos^2xdy=dx 3.cos^2xdy=(2+y)dx

[latex]1)\quad (x^2+1)dx=(3y^2-2)dy\\\\\int (x^2+1)dx=\int (3y^2-2)dy\\\\\frac{x^3}{3}+x=y^3-2y+C\\\\2)\quad cos^2x\, dy=dx\\\\\int dy=\int \frac{dx}{cos^2x}\\\\y=tgx+C\\\\3)\quad cos^2x\, dy=(2+y)dx\\\\\int \frac{dy}{2+y} =\int \frac{dx}{cos^2x}\\\\ln|2+y|=tgx+C [/latex]