方程2X²+（m²-9）x+m+1=0 ①两根互为倒数,求m的值.②两根互为相反数,求m的值.

方程2X²+（m²-9）x+m+1=0 ①两根互为倒数,求m的值.②两根互为相反数,求m的值.
方程2X²+（m²-9）x+m+1=0 ①两根互为倒数,求m的值.②两根互为相反数,求m的值.

方程2X²+（m²-9）x+m+1=0 ①两根互为倒数,求m的值.②两根互为相反数,求m的值.
方程2X²+（m²-9）x+m+1=0
①两根互为倒数,求m的值.
x1x2=1,
韦达定理：
x1x2=c/a=(m+1)/2=1,
m+1=2
m=1;
②两根互为相反数,求m的值.
x1+x2=0,
韦达定理：
x1+x2=-b/a=-(m²-9)/2=0,
m²-9=0
m1=3,m2=-3;

872m