f(x)+gx=2㏒²(1-x),..............(1)
f(-x)+g(-x)=-f(x)+g(x)=2log2(1+x).....(2)
(1)式+(2)式得:2g(x)=2log2(1-x)+2log2(1+x)=2log2((1-x)(1+x))=2log2(1-x^2),
g(x)=log2(1-x^2),在[-1,1]上单调递减,
(1)式-(2)式得:2f(x)=2log2(1-x)-2log2(1+x)=2log2((1-x)/(1+x))
f(x)=log2((1-x)/(1+x))=log2(2/(1+x)-1),在[-1,1]上单调递减
得用f(-x)=-f(x),g(-x)=g(x)代入已知式fx+gx=2㏒²(1-x),得2式子,把f(x),g(x)看作一个未知数,解方程组即可
同求同求!!!