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9.8E:练习

  • Page ID
    204391
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    练习成就完美

    使用以下命令简化表达式\(a^{\frac{1}{n}}\)

    在以下练习中,写成激进表达式。

    示例\(\PageIndex{47}\)
    1. \(x^{\frac{1}{2}}\)
    2. \(y^{\frac{1}{3}}\)
    3. \(z^{\frac{1}{4}}\)
    示例\(\PageIndex{48}\)
    1. \(r^{\frac{1}{2}}\)
    2. \(s^{\frac{1}{3}}\)
    3. \(t^{\frac{1}{4}}\)
    回答
    1. \(\sqrt{r}\)
    2. \(\sqrt[3]{s}\)
    3. \(\sqrt[4]{t}\)
    示例\(\PageIndex{49}\)
    1. \(u^{\frac{1}{5}}\)
    2. \(v^{\frac{1}{9}}\)
    3. \(w^{\frac{1}{20}}\)
    示例\(\PageIndex{50}\)
    1. \(g^{\frac{1}{7}}\)
    2. \(h^{\frac{1}{5}}\)
    3. \(j^{\frac{1}{25}}\)
    回答
    1. \(\sqrt[7]{g}\)
    2. \(\sqrt[5]{h}\)
    3. \(\sqrt[25]{j}\)
    在以下练习中,用有理指数书写。
    示例\(\PageIndex{51}\)
    1. \(−\sqrt[7]{x}\)
    2. \(\sqrt[9]{y}\)
    3. \(\sqrt[5]{f}\)
    示例\(\PageIndex{52}\)
    1. \(\sqrt[8]{r}\)
    2. \(\sqrt[10]{s}\)
    3. \(\sqrt[4]{t}\)
    回答
    1. \(r^{\frac{1}{8}}\)
    2. \(s^{\frac{1}{10}}\)
    3. \(t^{\frac{1}{4}}\)
    示例\(\PageIndex{53}\)
    1. \ (\ sqrt [3] {a}\
    2. \(\sqrt[12]{b}\)
    3. \(\sqrt{c}\)
    示例\(\PageIndex{54}\)
    1. \(\sqrt[5]{u}\)
    2. \(\sqrt{v}\)

    。

    回答
    1. \(u^{\frac{1}{5}}\)
    2. \(v^{\frac{1}{2}}\)
    3. \(w^{\frac{1}{16}}\)
    示例\(\PageIndex{55}\)
    1. \(\sqrt[3]{7c}\)
    2. \(\sqrt[7]{12d}\)
    3. \(3\sqrt[4]{5f}\)
    示例\(\PageIndex{56}\)
    1. \(\sqrt[4]{5x}\)
    2. \(\sqrt[8]{9y}\)
    3. \(7\sqrt[5]{3z}\)
    回答
    1. \((5x)^{\frac{1}{4}}\)
    2. \((9y)^{\frac{1}{8}}\)
    3. \(7(3z)^{\frac{1}{5}}\)
    示例\(\PageIndex{57}\)
    1. \(\sqrt{21p}\)
    2. \(\sqrt[4]{8q}\)
    3. \(\sqrt[6]{436r}\)
    示例\(\PageIndex{58}\)
    1. \(\sqrt[3]{25a}\)
    2. \(\sqrt{3b}\)

    。

    回答
    1. \((25a)^{\frac{1}{3}}\)
    2. \((3b)^{\frac{1}{2}}\)
    3. \((40c)^{\frac{1}{10}}\)

    在以下练习中,简化。

    示例\(\PageIndex{59}\)
    1. \(81^{\frac{1}{2}}\)
    2. \(125^{\frac{1}{3}}\)
    3. \(64^{\frac{1}{2}}\)
    示例\(\PageIndex{60}\)
    1. \(625^{\frac{1}{4}}\)
    2. \(243^{\frac{1}{5}}\)
    3. \(32^{\frac{1}{5}}\)
    回答
    1. 5
    2. 3
    3. 2
    示例\(\PageIndex{61}\)
    1. \(16^{\frac{1}{4}}\)
    2. \(16^{\frac{1}{2}}\)
    3. \(3125^{\frac{1}{5}}\)
    示例\(\PageIndex{62}\)
    1. \(216^{\frac{1}{3}}\)
    2. \(32^{\frac{1}{5}}\)
    3. \(81^{\frac{1}{4}}\)
    回答
    1. 6
    2. 2
    3. 3
    示例\(\PageIndex{63}\)
    1. \((−216)^{\frac{1}{3}}\)
    2. \(−216^{\frac{1}{3}}\)
    3. \((216)^{−\frac{1}{3}}\)
    示例\(\PageIndex{64}\)
    1. \((−243)^{\frac{1}{5}}\)
    2. \(−243^{\frac{1}{5}}\)
    3. \((243)^{−\frac{1}{5}}\)
    回答
    1. −3
    2. −3
    3. \(\frac{1}{3}\)
    示例\(\PageIndex{65}\)
    1. \((−1)^{\frac{1}{3}}\)
    2. \(−1^{\frac{1}{3}}\)
    3. \((1)^{−\frac{1}{3}}\)
    示例\(\PageIndex{66}\)
    1. \((−1000)^{\frac{1}{3}}\)
    2. \(−1000^{\frac{1}{3}}\)
    3. \((1000)^{−\frac{1}{3}}\)
    回答
    1. −10
    2. −10
    3. \ (\ frac {1} {10}
    示例\(\PageIndex{67}\)
    1. \((−81)^{\frac{1}{4}}\)
    2. \(−81^{\frac{1}{4}}\)
    3. \((81)^{−\frac{1}{4}}\)
    示例\(\PageIndex{68}\)
    1. \((−49)^{\frac{1}{2}}\)
    2. \(−49^{\frac{1}{2}}\)
    3. \((49)^{−\frac{1}{2}}\)
    回答
    1. 不是实数
    2. −7
    3. \(\frac{1}{7}\)
    示例\(\PageIndex{69}\)
    1. \((−36)^{\frac{1}{2}}\)
    2. \(−36^{\frac{1}{2}}\)
    3. \((36)^{−\frac{1}{2}}\)
    示例\(\PageIndex{70}\)
    1. \((−1)^{\frac{1}{4}}\)
    2. \((1)^{−\frac{1}{4}}\)
    3. \(−1^{\frac{1}{4}}\)
    回答
    1. 不是实数
    2. 1
    3. −1
    示例\(\PageIndex{71}\)
    1. \((−100)^{\frac{1}{2}}\)
    2. \(−100^{\frac{1}{2}}\)
    3. \((100)^{−\frac{1}{2}}\)
    示例\(\PageIndex{72}\)
    1. \((−32)^{\frac{1}{5}}\)
    2. \((243)^{−\frac{1}{5}}\)
    3. \(−125^{\frac{1}{3}}\)
    回答
    1. −2
    2. \(\frac{1}{3}\)
    3. −5

    使用以下命令简化表达式\(a^{\frac{m}{n}}\)

    在以下练习中,用有理指数书写。

    示例\(\PageIndex{73}\)
    1. \(\sqrt{m^5}\)
    2. \(\sqrt[3]{n^2}\)
    3. \(\sqrt[4]{p^3}\)
    示例\(\PageIndex{74}\)
    1. \(\sqrt[4]{r^7}\)
    2. \(\sqrt[5]{s^3}\)
    3. \(\sqrt[3]{t^7}\)
    回答
    1. \(r^{\frac{7}{4}}\)
    2. \(s^{\frac{3}{5}}\)
    3. \(t^{\frac{7}{3}}\)
    练习\(\PageIndex{75}\)
    1. \(\sqrt[5]{u^2}\)
    2. \(\sqrt[5]{v^8}\)
    3. \(\sqrt[9]{w^4}\)
    示例\(\PageIndex{76}\)
    1. \(\sqrt[3]{a}\)
    2. \(\sqrt[5]{b}\)
    3. \(\sqrt[3]{c^5}\)
    回答
    1. \(a^{\frac{1}{3}}\)
    2. \(b^{\frac{1}{5}}\)
    3. \(c^{\frac{5}{3}}\)
    在以下练习中,简化。
    示例\(\PageIndex{77}\)
    1. \(16^{\frac{3}{2}}\)
    2. \(8^{\frac{2}{3}}\)
    3. \(10,000^{\frac{3}{4}}\)
    示例\(\PageIndex{78}\)
    1. \(1000^{\frac{2}{3}}\)
    2. \(25^{\frac{3}{2}}\)
    3. \(32^{\frac{3}{5}}\)
    回答
    1. 100
    2. 125
    3. 8
    示例\(\PageIndex{79}\)
    1. \(275^{\frac{3}{2}}\)
    2. \(16^{\frac{5}{4}}\)
    3. \(32^{\frac{2}{5}}\)
    示例\(\PageIndex{80}\)
    1. \(16^{\frac{3}{2}}\)
    2. \(125^{\frac{5}{3}}\)
    3. \(64^{\frac{4}{3}}\)
    回答
    1. 64
    2. 3125
    3. 256
    示例\(\PageIndex{81}\)
    1. \(32^{\frac{2}{5}}\)
    2. \(27^{−\frac{2}{3}}\)
    3. \(25^{−\frac{3}{2}}\)
    示例\(\PageIndex{82}\)
    1. \(64^{\frac{5}{2}}\)
    2. \(81^{−\frac{3}{2}}\)
    3. \(27^{−\frac{4}{3}}\)
    回答
    1. 32,768
    2. \(\frac{1}{729}\)
    3. \(\frac{1}{81}\)
    示例\(\PageIndex{83}\)
    1. \(25^{\frac{3}{2}}\)
    2. \(9^{−\frac{3}{2}}\)
    3. \((−64)^{\frac{2}{3}}\)
    示例\(\PageIndex{84}\)
    1. \(100^{\frac{3}{2}}\)
    2. \(49^{−\frac{5}{2}}\)
    3. \((−100)^{\frac{3}{2}}\)
    回答
    1. 1000
    2. \(\frac{1}{16,807}\)
    3. 不是一个实数
    示例\(\PageIndex{85}\)
    1. \(−9^{\frac{3}{2}}\)
    2. \(−9^{−\frac{3}{2}}\)
    3. \((−9)^{\frac{3}{2}}\)
    示例\(\PageIndex{86}\)
    1. \(−64^{\frac{3}{2}}\)
    2. \(−64^{−\frac{3}{2}}\)
    3. \((−64)^{\frac{3}{2}}\)
    回答
    1. −512
    2. \(−\frac{1}{512}\)
    3. 不是实数
    示例\(\PageIndex{87}\)
    1. \(−100^{\frac{3}{2}}\)
    2. \(−100^{−\frac{3}{2}}\)
    3. \((−100)^{\frac{3}{2}}\)
    示例\(\PageIndex{88}\)
    1. \(−49^{\frac{3}{2}}\)
    2. \(−49^{−\frac{3}{2}}\)
    3. \((−49)^{\frac{3}{2}}\)
    回答
    1. −343
    2. \(−\frac{1}{343}\)
    3. 不是实数

    使用指数定律简化带有有理指数的表达式

    在以下练习中,简化。

    示例\(\PageIndex{89}\)
    1. \(4^{\frac{5}{8}}·4^{\frac{11}{8}}\)
    2. \(m^{\frac{7}{12}}·m^{\frac{17}{12}}\)
    3. \(p^{\frac{3}{7}}·p^{\frac{18}{7}}\)
    示例\(\PageIndex{90}\)
    1. \(6^{\frac{5}{2}}·6^{\frac{12}{6}}\)
    2. \(n^{\frac{2}{10}}·n^{\frac{8}{10}}\)
    3. \(q^{\frac{2}{5}}·q^{\frac{13}{5}}\)
    回答
    1. 216
    2. n
    3. \(q^3\)
    示例\(\PageIndex{91}\)
    1. \(5^{\frac{1}{2}}·5^{\frac{7}{2}}\)
    2. \(c^{\frac{3}{4}}·c^{\frac{9}{4}}\)
    3. \(d^{\frac{3}{5}}·d^{\frac{2}{5}}\)
    示例\(\PageIndex{92}\)
    1. \(10^{\frac{1}{3}}·10^{\frac{5}{3}}\)
    2. \(x^{\frac{5}{6}}·x^{\frac{7}{6}}\)
    3. \(y^{\frac{11}{8}}·y^{\frac{21}{8}}\)
    回答
    1. 100
    2. \(x^2\)
    3. \(y^4\)
    示例\(\PageIndex{93}\)
    1. \((m^6)^{\frac{5}{2}}\)
    2. \((n^9)^{\frac{4}{3}}\)
    3. \((p^{12})^{\frac{3}{4}}\)
    示例\(\PageIndex{94}\)
    1. \((a^{12})^{\frac{1}{6}}\)
    2. \((b^{15})^{\frac{3}{5}}\)
    3. \((c^{11})^{\frac{1}{11}}\)
    回答
    1. \(a^2\)
    2. \(b^9\)
    3. c
    示例\(\PageIndex{95}\)
    1. \((x^{12})^{\frac{2}{3}}\)
    2. \((y^{20})^{\frac{2}{5}}\)
    3. \((z^{16})^{\frac{1}{16}}\)
    示例\(\PageIndex{96}\)
    1. \((h^6)^{\frac{4}{3}}\)
    2. \((k^{12})^{\frac{3}{4}}\)
    3. \((j^{10})^{\frac{7}{5}}\)
    回答
    1. \(h^8\)
    2. \(k^9\)
    3. \(j^{14}\)
    示例\(\PageIndex{97}\)
    1. \(\frac{x^{\frac{7}{2}}}{x^{\frac{5}{2}}}\)
    2. \(\frac{y^{\frac{5}{2}}}{y^{\frac{1}{2}}}\)
    3. \(\frac{r^{\frac{4}{5}}}{r^{\frac{9}{5}}}\)
    示例\(\PageIndex{98}\)
    1. \(\frac{s^{\frac{11}{5}}}{s^{\frac{6}{5}}}\)
    2. \(\frac{z^{\frac{7}{3}}}{z^{\frac{1}{3}}}\)
    3. \(\frac{w^{\frac{2}{7}}}{w^{\frac{9}{7}}}\)
    回答
    1. s
    2. \(z^2\)
    3. \(\frac{1}{w}\)
    示例\(\PageIndex{99}\)
    1. \(\frac{t^{\frac{12}{5}}}{t^{\frac{7}{5}}}\)
    2. \(\frac{x^{\frac{3}{2}}}{x^{\frac{1}{2}}}\)
    3. \(\frac{m^{\frac{13}{8}}}{m^{\frac{5}{8}}}\)
    示例\(\PageIndex{100}\)
    1. \(\frac{u^{\frac{13}{9}}}{u^{\frac{4}{9}}}\)
    2. \(\frac{r^{\frac{15}{7}}}{r^{\frac{8}{7}}}\)
    3. \(\frac{n^{\frac{3}{5}}}{n^{\frac{8}{5}}}\)
    回答
    1. r
    2. \(\frac{1}{n}\)
    示例\(\PageIndex{101}\)
    1. \((9p^{\frac{2}{3}})^{\frac{5}{2}}\)
    2. \((27q^{\frac{3}{2}})^{\frac{4}{3}}\)
    示例\(\PageIndex{102}\)
    1. \((81r^{\frac{4}{5}})^{\frac{1}{4}}\)
    2. \((64s^{\frac{3}{7}})^{\frac{1}{6}}\)
    回答
    1. \(3r^{\frac{1}{5}}\)
    2. \(2s^{\frac{1}{14}}\)
    示例\(\PageIndex{103}\)
    1. \((16u^{\frac{1}{3}})^{\frac{3}{4}}\)
    2. \((100v^{\frac{2}{5}})^{\frac{3}{2}}\)
    示例\(\PageIndex{104}\)
    1. \((27m^{\frac{3}{4}})^{\frac{2}{3}}\)
    2. \((625n^{\frac{8}{3}})^{\frac{3}{4}}\)
    回答
    1. \(9m^{\frac{1}{2}}\)
    2. \(125n^2\)
    示例\(\PageIndex{105}\)
    1. \((x^{8}y^{10})^{\frac{1}{2}}\)
    2. \((a^{9}by ^{12})^{\frac{1}{3}}\)
    示例\(\PageIndex{106}\)
    1. \((r^{8}s^{4})^{\frac{1}{4}}\)
    2. \((u^{15}v^{20})^{\frac{1}{5}}\)
    回答
    1. \(r^{2}s\)
    2. \(u^{3}v^{4}\)
    示例\(\PageIndex{107}\)
    1. \((a^{6}b^{16})^{\frac{1}{2}}\)
    2. \((j^{9}k^{6})^{\frac{2}{3}}\)
    示例\(\PageIndex{108}\)
    1. \((r^{16}s^{10})^{\frac{1}{2}}\)
    2. \((u^{10}v^5)^{\frac{4}{5}}\)
    回答
    1. \(r^{8}s^{5}\)
    2. \(u^{8}v^{4}\)
    示例\(\PageIndex{109}\)
    1. \(\frac{r^{\frac{5}{2}}·r^{−\frac{1}{2}}}{r^{−\frac{3}{2}}}\)
    2. \(\frac{s^{\frac{1}{5}}·s}{s^{−\frac{9}{5}}}\)
    示例\(\PageIndex{110}\)
    1. \(\frac{a^{\frac{3}{4}}·a^{−\frac{1}{4}}}{a^{−\frac{10}{4}}}\)
    2. \(\frac{b^{\frac{2}{3}}·b}{b^{−\frac{7}{3}}}\)
    回答
    1. \(a^3\)
    2. \(b^4\)
    示例\(\PageIndex{111}\)
    1. \(\frac{c^{\frac{5}{3}}·c^{−\frac{1}{3}}}{c^{−\frac{2}{3}}}\)
    2. \(\frac{d^{\frac{3}{5}}·d}{d^{−\frac{2}{5}}}\)
    示例\(\PageIndex{112}\)
    1. \(\frac{m^{\frac{7}{4}}·m^{−\frac{5}{4}}}{m^{−\frac{2}{4}}}\)
    2. \(\frac{n^{\frac{3}{7}}·n}{n^{−\frac{4}{7}}}\)
    回答
    1. m
    2. \(n^2\)
    示例\(\PageIndex{113}\)

    \(4^{\frac{5}{2}}·4^{\frac{1}{2}}\)

    示例\(\PageIndex{114}\)

    \(n^{\frac{2}{6}}·n^{\frac{4}{6}}\)

    回答

    n

    示例\(\PageIndex{115}\)

    \((a^24)^ {\frac{1}{6}}\)

    示例\(\PageIndex{116}\)

    \((b^{10})^{\frac{3}{5}}\)

    回答

    \(b^6\)

    示例\(\PageIndex{117}\)

    \(\frac{w^{\frac{2}{5}}}{w^{\frac{7}{5}}}\)

    示例\(\PageIndex{118}\)

    \(\frac{z^{\frac{2}{3}}}{z^{\frac{8}{3}}}\)

    回答

    \(\frac{1}{z^2}\)

    示例\(\PageIndex{119}\)

    \((27r^{\frac{3}{5}})^{\frac{1}{3}}\)

    示例\(\PageIndex{120}\)

    \((64s^{\frac{3}{5}})^{\frac{1}{6}}\)

    回答

    \(2s^{\frac{1}{10}}\)

    示例\(\PageIndex{121}\)

    \((r^{9}s^{12})^{\frac{1}{3}}\)

    示例\(\PageIndex{122}\)

    \((u^{12}v^{18})^{\frac{1}{6}}\)

    回答

    \(u^{2}v^{3}\)

    日常数学

    示例\(\PageIndex{123}\)

    园林绿化 Joe 想在他的后院有一块方形的花园。 他有足够的堆肥来覆盖 144 平方英尺的面积。 简化\(144^{\frac{1}{2}}\)即可找到他花园两边的长度。

    示例\(\PageIndex{124}\)

    园林绿化 Elliott 想在院子里建一个方形露台。 他有足够的混凝土来铺设面积为242平方英尺的面积。 简化\(242^{\frac{1}{2}}\)即可找到他露台两侧的长度。四舍五入到最接近的十分之一英尺。

    回答

    15.6 英尺

    示例\(\PageIndex{125}\)

    Gravity 在摆放节日装饰品时,鲍勃从一棵高 12 英尺的树顶上掉下了一个装饰品。 简化\(\frac{12^{\frac{1}{2}}}{16^{\frac{1}{2}}}\)以找出装饰品到达地面花了多少秒钟。 四舍五入到最接近的十分之一秒。

    示例\(\PageIndex{126}\)

    Gravity 一架飞机从湖上 1024 英尺的高度投下了一枚照明弹。 简化\(\frac{1024^{\frac{1}{2}}}{16^{\frac{1}{2}}}\)以找出照明弹到达水中花费了多少秒。

    回答

    8 秒

    写作练习

    示例\(\PageIndex{127}\)

    显示两种不同的代数方法以进行简化\(4^{\frac{3}{2}}\)。 解释你的所有步骤。

    示例\(\PageIndex{128}\)

    解释为什么\((−16)^{\frac{3}{2}}\)无法计算表达式。