x=√2+√3,x^8+1=x^4(6y+16) 求y
问题描述：
x=√2+√3,x^8+1=x^4(6y+16) 求y
答
x^8+1=x^4(6y+16)
得6y+16
=（x^8+1）/x^4
=x^4+1/x^4
=(x^2+1/x^2)^2-2x^2
=(√2+√3)^2
=5+2√6 ;
1/x^2
=5-2√6
故6y+16
=（5+2√6+5-2√6）^2-2
=98,
y=（98-16）/6
=41/3