(X×X)/[(b-X)×(b-X)]=0.36/0.72
问题描述:
(X×X)/[(b-X)×(b-X)]=0.36/0.72
怎么算得X=0.41b?求详解
答
x² / (b-x)² = 1/2
左右两边同时开平方
x /(b-x) = √2 / 2
x = (√2 -1) b
= (1.41 -1)b
=0.41b