xe2718的精选

问题详情：已知f(x)=ex-e-x,g(x)=ex+e-x(e=2.718…).(1)则[f(x)]2-[g(x)]2的值为; (2)若f(x)·f(y)=4,g(x)·g(y)=8,则=. 【回答】(1)-4(2)3(1)[f(x)]2-[g(x)]2=[f(x)+g(x)][f(x)-g(x)]=[(ex-e-x)+(ex+e-x)][(ex-e-x)...