Question

(a^n-5^n)/(a^n+5^n) 求极限 n趋近于无穷

Answer 1

a=5的时候(a^n-5^n)/(a^n+5^n)=0

当a>5的时候,同时除以a^n得(a^n-5^n)/(a^n+5^n)= (1-(5/a)^n) / (1+(5/a)^n) = 1

当a