三角形abc的三边abc的倒数成等差数列，求证B>90°

在三角形ABC中,其三边abc的倒数成等差数列,求证B＜90°在三角形ABC中,其三边abc的倒数成等差数列,求证B＜90°在三角形ABC中,其三边abc的倒数成等差数列,求证B＜90°假设B>＝90

三角形ABC的三边abc的倒数成等差数列,求证B＜90度三角形ABC的三边abc的倒数成等差数列,求证B＜90度三角形ABC的三边abc的倒数成等差数列,求证B＜90度2/b=1/a+1/cb=2ac

三角形ABC三边a.b.c的倒数成等差数列求证B小于90度三角形ABC三边a.b.c的倒数成等差数列求证B小于90度三角形ABC三边a.b.c的倒数成等差数列求证B小于90度2/b=1/a+1/c得到

已知三角形ABC的三边a.b.c.的倒数成等差数列,求证B已知三角形ABC的三边a.b.c.的倒数成等差数列,求证B已知三角形ABC的三边a.b.c.的倒数成等差数列,求证B已知三角形ABC的三边a.

三角形ABC的三边a,b,c的倒数成等差数列,求证B＜π/2三角形ABC的三边a,b,c的倒数成等差数列,求证B＜π/2三角形ABC的三边a,b,c的倒数成等差数列,求证B＜π/2反正法设B>=π/2

三角形ABC的三边a,b,c的倒数成等差数列,求证B>π/2度三角形ABC的三边a,b,c的倒数成等差数列,求证B>π/2度三角形ABC的三边a,b,c的倒数成等差数列,求证B>π/2度由题意2/b=

三角形ABC的三边a,b,c的倒数成等差数列,求证B三角形ABC的三边a,b,c的倒数成等差数列,求证B三角形ABC的三边a,b,c的倒数成等差数列,求证Ba,b,c的倒数成等差数列1/a+1/c=2

三角形ABC的三边a,b,c的倒数成等差数列,求证B三角形ABC的三边a,b,c的倒数成等差数列,求证B三角形ABC的三边a,b,c的倒数成等差数列,求证B你都说明白了...假设B>=90度那么b>a

在三角形abc的三边a,b,c的倒数成等差数列,求证b在三角形abc的三边a,b,c的倒数成等差数列,求证b在三角形abc的三边a,b,c的倒数成等差数列,求证b1/a+1/c=2/bb=2/(1/a

三角形ABC的三边a,b,c的倒数成等差数列,求证B三角形ABC的三边a,b,c的倒数成等差数列,求证B三角形ABC的三边a,b,c的倒数成等差数列,求证B2/b=1/a+1/c,a,b,c>0b=2

三角形ABC的三边a,b,c的倒数成等差数列,求证B三角形ABC的三边a,b,c的倒数成等差数列,求证B三角形ABC的三边a,b,c的倒数成等差数列,求证B显然若1/a,1/b,1/c成等差.那么总有

已知三角形ABC三边abc的倒数成等差数列,证明：角B为锐角已知三角形ABC三边abc的倒数成等差数列,证明：角B为锐角已知三角形ABC三边abc的倒数成等差数列,证明：角B为锐角设三边为a,b,c则

△ABC的三边a,b,c的倒数成等差数列,求证B△ABC的三边a,b,c的倒数成等差数列,求证B△ABC的三边a,b,c的倒数成等差数列,求证B证明：2/b=1/a+1/c2/sinB=1/sinA+

△ABC的三边a,b,c的倒数成等差数列,求证B＜π/2△ABC的三边a,b,c的倒数成等差数列,求证B＜π/2△ABC的三边a,b,c的倒数成等差数列,求证B＜π/2用,余弦定理,正弦定理,

△ABC的三边a,b,c的倒数成等差数列,求证B△ABC的三边a,b,c的倒数成等差数列,求证B△ABC的三边a,b,c的倒数成等差数列,求证B由题得1/a+1/c=2/b则b=2/(1/a+1/c)

△ABC的三边abc的倒数成等差数列,求证B小于π/2△ABC的三边abc的倒数成等差数列,求证B小于π/2△ABC的三边abc的倒数成等差数列,求证B小于π/22/b=1/a+1/c=(a+c)/a

三角型ABC的三边A,B,C的倒数成等差数列,求证B<90度.用反证法三角型ABC的三边A,B,C的倒数成等差数列,求证B<90度.用反证法三角型ABC的三边A,B,C的倒数成等差数列,求

三角形ABC的三边长abc的倒数成等差数列求证B三角形ABC的三边长abc的倒数成等差数列求证B三角形ABC的三边长abc的倒数成等差数列求证B应该由题有1/a+1/c=2/b,且a+c>b,a>0,

三角形ABC三边长a,b,c,的倒数成等差数列,求证：角B小于90°三角形ABC三边长a,b,c,的倒数成等差数列,求证：角B小于90°三角形ABC三边长a,b,c,的倒数成等差数列,求证：角B小于9

已知a,b,c是三角形ABC的三边,若a,b,c的倒数成等差数列,求证角B为锐角已知a,b,c是三角形ABC的三边,若a,b,c的倒数成等差数列,求证角B为锐角已知a,b,c是三角形ABC的三边,若a