计算:-22+(12-1)0+2sin30°+x2-1x2-2x+1+x2-2xx-2÷x,其中x=12.-数学

题目简介

计算:-22+(12-1)0+2sin30°+x2-1x2-2x+1+x2-2xx-2÷x,其中x=12.-数学

题目详情

计算:-22+(
1
2
-1
0+2sin30°+
x2-1
x2-2x+1
+
x2-2x
x-2
÷x,其中x=
1
2
题型:解答题难度:中档来源:万州区模拟

答案

原式=-4+1+2•class="stub"1
2
+
(x+1)(x-1)
(x-1) 2
+
x(x-2)
x-2
class="stub"1
x

=-2+class="stub"x+1
x-1
+1
=class="stub"x+1
x-1
-1
=class="stub"2
x-1

当x=class="stub"1
2
时,原式=class="stub"2
class="stub"1
2
-1
=-4.

更多内容推荐