(1)(2+根号3)^2-(2-根号3)^2
解:(2+√3)^2-(2-√3)^2
=(4+2*2*√3+3)-(4-2*2*√3+3)
=8√3
(2)化简1/2-根号3
解:1/(2-√3)
=(2+√3)/(2+√3)*(2-√3)
=(2+√3)/(4-3)
=(2+√3)
(3)计算(根号6-2倍根号3)^2-6(3-根号3)
解:(√6-2√3)^2-6(3-√3)
=(6-2*√6*2√3+12)-18+6√3
=18-12√2-18+6√3
=6(√3-2√2)
(4)已知:根号a+根号b=根号3+根号2,根号ab=根号6-根号2,a+b=
解:a+b
=a+2√ab+b-2√ab
=(√a+√b)^2-2√ab
=(√3+√2)^2-2(√6-√2)
=(3+2*√3*√2+2)-2(√6-√2)
=5+2√6-2√6+2√2
=5-2√2