问题
解答题
先化简,再求值:
|
答案
÷(1+x x2-1
)=1 x-1
÷x x2-1 x-1+1 x-1
=
×x (x+1)(x-1) x-1 x
=
.1 x+1
x=2cos30°-(
)0=2×3
-1=3 2
-1.3
∴当x=
-1时,3
原式=
=1 x+1
=1
-1+13
=1 3
.3 3
先化简,再求值:
|
÷(1+x x2-1
)=1 x-1
÷x x2-1 x-1+1 x-1
=
×x (x+1)(x-1) x-1 x
=
.1 x+1
x=2cos30°-(
)0=2×3
-1=3 2
-1.3
∴当x=
-1时,3
原式=
=1 x+1
=1
-1+13
=1 3
.3 3