Asphere has a radius of 6 meters. a second sphere has a radius of 3 meters. what is the difference of the volumes of the spheres?

Find csc x if sin x + cot x cos x =√3 a. 9 b. 3 c. √(3)/2 d. √(3)

Ineed with number 17 i don’t get it at alll

Assume that there is a 11% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?