If alpha_(1), alpha_(2) and alpha_(3) are the coefficients of linear expansion of a solid along three mutually perpendicular directions, find the average coefficient of volume expansion of that material?

If alpha_(1), alpha_(2) and alpha_(3) are the coefficients of linear e

1.	If alpha_(1), alpha_(2) and alpha_(3) are the coefficients of linear expansion of a solid along three mutually perpendicular directions, find the average coefficient of volume expansion of that material?
Answer» SOLUTION :`alpha_(1)+alpha_(2)+alpha_(3)`