1.化简求值.(1){(4b√a/b)+(2/b√ab^3)} (b>0)(2)若x=√2+1,y=√2-1,求x^2+xy+y^_数学解答

1.化简求值.
(1){(4b√a/b)+(2/b√ab^3)} (b>0)
(2)若x=√2+1,y=√2-1,求x^2+xy+y^2的值
2.已知a-b=√12,ab=1,b>0,求a+b值
3.已知x^2+(1/x^2)=14,且x>1,求(x^2+1)/x和(x^2-1)/x的值

人气：389 ℃　时间：2020-05-25 05:42:44

解答

(4b√a/b)+(2/b√ab^3) (b>0)
=4√ab+2√ab=6√ab
x^2+xy+y^2=（x+y)^2=(2√2)^2=8
(a-b)^2+4ab=12+4=16
{(x^2+1)/x}^2=x^2+(1/x^2)+2=16 (x^2+1)/x=4
[(x^2-1)/x]^2=x^2+(1/x^2)-2=12
(x^2-1)/x=√12