Calculate correlation coefficient from the following data

X 73 74 76 70 74 72 75 72 78 72 87

Y 79 81 69 68 69 77 79 91 80 76 60

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.