(1)1初根号2-根号3,(要过程答案)
1/(根号2-根号3)
=(根号2+根号3)/[(根号2-根号3)(根号2+根号3)]
=(根号2+根号3)/[(根号2)^2-(根号3)^2]
=(根号2+根号3)/(2-3)
=-(根号2+根号3)
=-3.146
(2)3×根号5+2×(根号5-根号3)(要过程答案)
(保留3个有效数字)
3×根号5+2×(根号5-根号3)
=3根号5+2根号5-2根号3
=5根号5-2根号3
=7.716
(3)3×根号5+2×(根号5-根号3)(要过程答案)
和2题一样