(1)方程lg(4^x+2)=lg2^x+lg3的解为?
lg=log10
lg(4^x+2)=lg2^x+lg3
t^2-3t+2=0
(t-1)(t-2)=0
t1=1,t2=2
t1=1=2^x ===>x=0,
t2=2=2^x ====>x=1.
即解为0 和1
(2)化简(√5)^log5 (-a)^2的结果为?
5^(1/2)*log5(-a)^2=5^log5|a|=|a|
(1)方程lg(4^x+2)=lg2^x+lg3的解为?
lg=log10
lg(4^x+2)=lg2^x+lg3
t^2-3t+2=0
(t-1)(t-2)=0
t1=1,t2=2
t1=1=2^x ===>x=0,
t2=2=2^x ====>x=1.
即解为0 和1
(2)化简(√5)^log5 (-a)^2的结果为?
5^(1/2)*log5(-a)^2=5^log5|a|=|a|