(1)计算:2?1?(π?2011)0+2cos45°.(2)解方程:x2=3x+18

(1)计算:2?1?(π?2011)0+2cos45°.(2)解方程:x2=3x+18.
2025-12-17 04:20:36
推荐回答(1个)
回答1:

(1)原式=

1
2
-1+
2
×
2
2
=
1
2

(2)方程变形得:x2-3x-18=0,即(x-6)(x+3)=0,
可得x-6=0或x+3=0,
解得:x1=6,x2=-3.