共50条信息
下列说法正确的个数
\(①2\)的平方根是\(\sqrt{2}\) ;\(②\) \( \sqrt{5a}与 \sqrt{0.2a} \) 是同类二次根式;
\(③ \sqrt{2}-1与 \sqrt{2}+1 \)互为倒数; \(④\) \( \sqrt{3}-2 \)的绝对值是\(2- \sqrt{3} \)
如下是小明对问题作出的判断,
\((1){{a}^{0}}=1(√)\)
\((2)\sqrt{64}=\pm 8(×)\)
\((3)\)单项式\(-\dfrac{2{{x}^{2}}y}{5}\)的系数是\(-2(×)\)
\((4)\)倒数是它本身的数是\(\pm 1(√)\)
\((5)\)把\(-0.00041\)写成科学计数法是\(-4.1\times {{10}^{-4}}(√)\);
若每小题\(20\)分,则他的得分应是
\(a\)是不为\(1\)的有理数,我们把\( \dfrac{1}{1-a} \)称为\(a\)的差倒数\(.\)如:\(2\)的差倒数是\( \dfrac{1}{1-2}=-1 \),\(-1\)的差倒数是\( \dfrac{1}{1-\left(-1\right)}= \dfrac{1}{2} .\)已知\({a}_{1}=- \dfrac{1}{3} \),\({a}_{2} \)是\({a}_{1} \)的差倒数,\({a}_{3} \)是\({a}_{2} \)的差倒数,\({a}_{4} \)是\({a}_{3} \)的差倒数,\(…\),依此类推,\(a_{2017}\)的差倒数\({{a}_{2018}}=\)___ __.
定义:\(a\)是不为\(1\)的有理数,我们把\( \dfrac{1}{1-a} \)称为\(a\)的差倒数,如\(2\)的差倒数是\( \dfrac{1}{1-2} \)\(=-1\),\(-1\)的差倒数是\( \dfrac{1}{1-(-1)}= \dfrac{1}{2} \) \(.\)已知\(a_{1}=\)\(- \dfrac{1}{3} \) ,\(a_{2}\)是\(a_{1}\)的差倒数,\(a_{3}\)是\(a_{2}\)的差倒数,\(a_{4}\)是\(a_{3}\)的差倒数,\(…\),依此类推,则\((1)a_{2}=\)______,\((2)a_{2\;016}=\)______.
若\(a\)是不为\(1\)的有理数,我们把\( \dfrac{1}{1-a} \)称为\(a\)的差倒数\(.\)已知\({a}_{1}=- \dfrac{1}{3} \),\({a}_{2} \)是\({a}_{1} \)的差倒数,\({a}_{3} \)是\({a}_{2} \)的差倒数,\({a}_{4} \)是\({a}_{3} \)的差倒数,\(…\),依此类推,则\({a}_{2010}= \)________.
\(a\)是不为\(1\)的有理数,我们把\(\dfrac{1}{1-a}\)称为\(a\)的差倒数\(.\)如:\(3\)的差倒数是\(\dfrac{1}{1-3}=-\dfrac{1}{2}\),\(-1\)的差倒数是\(\dfrac{1}{1-(-1)}=\dfrac{1}{2}.\)已知\(a_{1}=2\),\(a_{2}\)是\(a_{1}\)的差倒数,\(a_{3}\)是\(a_{2}\)的差倒数,\(a_{4}\)是\(a_{3}\)的差倒数,\(…\),依此类推,则\(a_{15}=\)____________.
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