求绝对值和简单计算题.

题目

求绝对值和简单计算题.
求下列各数的绝对值:
(1)三次根号-8,(2)根号17,(3)根号2/-3,(4)根号3-1.7,(5)1.4-根号2
计算题:精确到0.01
(1)根号5-根号3+0.145
(2)三次根号6-(圆周率)-根号2
(3)根号10+2.23-(圆周率)
(4) (-4)x根号7+2又根号6(结果保留三个有效数字)
答对计算题的3和4题另外有分加...

答案

(1)
∣三次根号-8∣
=∣-2∣
=2
(2)∣√17∣=√17
(3)∣(√2)/-3∣= (√2)/3
(4)∣√3-1.7∣=√3-1.7
(5)∣1.4-√2∣=√2-1.4
计算题:精确到0.01
(1)根号5-根号3+0.145
=2.236-1.732+0.145
=0.649
=0.65
(2)三次根号6-(圆周率)-根号2
=1.817-3.142-1.414
=-2.739
=-2.74
(3)根号10+2.23-(圆周率)
=3.162+2.23-3.142
=2.25
(4) (-4)x√7+2√6(结果保留三个有效数字)
=(-4)x2.646+2x2.449
=-10.584+4.898
=-5.686
=-5.69