If V=cos^- x+y / √x +√y then verify that cosV =x+y / √x +√y is a homogeneous function of x,y of degree 1/2 prove that x dV / ds +y dV / dy + 1/2 cotV =0

the diameter of a roller is 84 cm and its length is 120 cm. it takes 500 complete revolution to  move once over to level a playground. find the area of the playground in square m?

Find dy/DX when y=x^sinx+sin-1√x.

 

Please give me the solution of this problem. 

Solve the differential equation y’’+2ty’-4y=1, y(0)=y’(0)=0.