Question

1.已知a*a-3a+1=0,求(a*a*a)/(a*a*a*a*a*a+a*a*a+1)的值

Answer 1

第一题设a^2 -3a + 1 =0的两个根为a1,a2a1+a2 =3,a1*a2=1 推得a2 = 1/(a1)所以a1+[1/(a1)] =3(a^6+a^3+1)/(a^3) = a^3 +[1/(a^3)]+ 1= {[a+(1/a)]^3}-3a-3(1/a) + 1={[a+(1/a)]^3}-3[a+(1/a)] + 1=27-3*3+1=19所以(a...