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一道二次根式求值题已知x=1/√3+√2求x^3+(2√2+1)x^2+(√2-1)x

题目详情
一道二次根式求值题
已知x=1/√3+√2
求x^3+(2√2+1)x^2+(√2-1)x
▼优质解答
答案和解析
x=1/√3+√2 =√3-√2
x^3+(2√2+1)x^2+(√2-1)x
=x[x^2+(2√2+1)x+√2-1]
=x[3+2-2√6+(2√2+1)(√3-√2)+√2-1]
=(√3-√2)[5-2√6+2√6-4+√3-√2+√2-1]
=(√3-√2)*√3
=3-√6