Question

对数方程与指数方程log3(x-1)+ log3(x+1)=1的解集,

Answer 1

x-1>0 x>1 x+1>0 x>-1

log3(x-1)+ log3(x+1)=1

log3(x-1)(x+1)=log33

(x-1)(x+1)=3

x^2-1=3

x^2=4

x=2 x=-2(舍)