Question

设a2+2a-1=0,b4-2b2-1=0,且1-ab2≠0,则 =________.

Answer 1

a^2+2a-1=0
a^2+2a+1=2
(a+1)^2=2
a+1=±√2
a=-1±√2
b^4-2b^2-1=0 =>b^2=1+√2
∵1-ab^2不等于0
∴a=-1-√2

Answer 2

由题可知，a^2+2a-1=0,所以(a+1)^2=2,a=-根号2-1或者a=根本2-1，同理，所以(b^2-1)^2=2,b=（-根号2+1）^1/2或者b=（根号2+1）^1/2,且ab^2不等于1时，所以，当a=-根号2-1时，b=（根号2+1）^1/2。当a=根本2-1时，b=（-根号2+1）^1/2。