Question

已知a^2-3a+1=0,求a^2/a^4+1的值

Answer 1

解：因为：a^2-3a+1=0所以：a^2=3a-1，a^4=(3a-1)^2=9a^2-6a+1=27a-9-6a+1=21a-8。那么：a^2/(a^4+1)=(3a-1)/(21a-8+1)=1/7。