计算:(3√6-5√2)/(8-4√3+√6-√2) (分母有理化)
问题描述:
计算:(3√6-5√2)/(8-4√3+√6-√2) (分母有理化)
答
(3√6-5√2)/(8-4√3+√6-√2)
=(3√6-5√2)/【(√6-√2)²+(√6-√2)】
=(3√6-5√2)/【(√6-√2)(√6-√2+1)】
=(3√6-3√2)/【(√6-√2)(√6-√2+1)】-(2√2)/【(√6-√2)(√6-√2+1)】
=3/【(√6-√2+1)】-2/【(√3-1)(√6-√2+1)】
=3/【(√6-√2+1)】-2(√3+1)/【(√3-1)(√3+1)(√6-√2+1)】
=3/【(√6-√2+1)】-(√3+1)/【(√6-√2+1)】
=(3-√3-1)/(√6-√2+1)
=(3-√3-1)(√6-√2-1)/(√6-√2+1)(√6-√2-1)
=(3-√3-1)(√6-√2-1)/(8-4√3-1)
=(3-√3-1)(√6-√2-1)/(7-4√3)
=(3-√3-1)(√6-√2-1)(7+4√3)/(7-4√3)(7+4√3)
=(3-√3-1)(√6-√2-1)(7+4√3)神一般的计算能力。。。其实中间步骤是为了便于看出推导结果的详细过程,可以忽略的,也就是不断的通过分子分母乘以相同的数来凑平方差实现有理化