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8.7: Additional exercises

  • Page ID
    149521
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    These problems require the techniques of this chapter, and are in no particular order. Some problems may be done in more than one way.

    Exercises \(\PageIndex{}\)

    Exercise \(\PageIndex{1}\)

    \(\displaystyle\int(t+4)^3\,dt\)

    Answer

    \(\dfrac{(t+4)^4}{4}+C\)

    Exercise \(\PageIndex{2}\)

    \(\displaystyle\int t(t^2-9)^{3/2}\,dt\)

    Answer

    \(\dfrac{(t^2-9)^{5/2}}{5}+C\)

    Exercise \(\PageIndex{3}\)

    \(\displaystyle\int(e^{t^2}+16)te^{t^2}\,dt\)

    Answer

    \(\dfrac{(e^{t^2}+16)^2}{4}+C\)

    Exercise \(\PageIndex{4}\)

    \(\displaystyle\int\sin t\cos 2t\,dt\)

    Answer

    \(\cos t-\dfrac{2\cos^3 t}{3}+C\)

    Exercise \(\PageIndex{5}\)

    \(\displaystyle\int \tan t\sec^2t\,dt\)

    Answer

    \(\dfrac{\tan^2 t}{2}+C\)

    Exercise \(\PageIndex{6}\)

    \(\displaystyle\int {2t+1\over t^2+t+3}\,dt\)

    Answer

    \(\ln\big|t^2+t+3\big|+C\)

    Exercise \(\PageIndex{7}\)

    \(\displaystyle\int {1\over t(t^2-4)}\,dt\)

    Answer

    \(\dfrac{1}{8}\ln\left(\big|1-\dfrac{4}{t^2}\big|\right)+C\)

    Exercise \(\PageIndex{8}\)

    \(\displaystyle\int {1\over (25-t^2)^{3/2}}\,dt\)

    Answer

    \(\dfrac{1}{25}\tan\big(\arcsin(t/5)\big)+C=\dfrac{t}{25\sqrt{25-t^2}}+C\)

    Exercise \(\PageIndex{9}\)

    \(\displaystyle\int {\cos 3t\over\sqrt{\sin3t}}\,dt\)

    Answer

    \(\dfrac{2\sqrt{\sin 3t}}{3}+C\)

    Exercise \(\PageIndex{10}\)

    \(\displaystyle\int t\sec^2 t\,dt\)

    Answer

    \(t\tan t-\ln\big|\sec t\big|+C\)

    Exercise \(\PageIndex{11}\)

    \(\displaystyle\int {e^t\over \sqrt{e^t+1}}\,dt\)

    Answer

    \(2\sqrt{e^t+1}+C\)

    Exercise \(\PageIndex{12}\)

    \(\displaystyle\int \cos^4 t\,dt\)

    Answer

    \(\dfrac{3t}{8}+\dfrac{\sin 2t}{4}+\dfrac{\sin 4t}{32}+C\)

    Exercise \(\PageIndex{13}\)

    \(\displaystyle\int {1\over t^2+3t}\,dt\)

    Answer

    \(\dfrac{1}{3}\ln\left|\dfrac{t}{t+3}\right|+C\)

    Exercise \(\PageIndex{14}\)

    \(\displaystyle\int {1\over t^2\sqrt{1+t^2}}\,dt\)

    Answer

    \(\dfrac{-1}{\sin(\arctan t)}+C=-\dfrac{\sqrt{1+t^2}}{t}+C\)

    Exercise \(\PageIndex{15}\)

    \(\displaystyle\int {\sec^2t\over (1+\tan t)^3}\,dt\)

    Answer

    \(\dfrac{-1}{2(1+\tan t)^2}+C\)

    Exercise \(\PageIndex{16}\)

    \(\displaystyle\int t^3\sqrt{t^2+1}\,dt\)

    Answer

    \(\dfrac{(t^2+1)^{5/2}}{5}-\dfrac{(t^2+1)^{3/2}}{3}+C=\dfrac{t^2(t^2+1)^{3/2}}{3}-\dfrac{2(t^2+1)^{5/2}}{15}+C\)

    Exercise \(\PageIndex{17}\)

    \(\displaystyle\int e^t\sin t\,dt\)

    Answer

    \(\dfrac{e^t}{2}(\sin t-\cos t)+C\)

    Exercise \(\PageIndex{18}\)

    \(\displaystyle\int (t^{3/2}+47)^3\sqrt{t}\,dt\)

    Answer

    \(\dfrac{(t^{3/2}+47)^4}{6}+C\)

    Exercise \(\PageIndex{19}\)

    \(\displaystyle\int {t^3\over (2-t^2)^{5/2}}\,dt\)

    Answer

    \(\dfrac{2}{3(2-t^2)^{3/2}}-\dfrac{1}{(2-t^2)^{1/2}}+C=\dfrac{t^2-(4/3)}{(2-t^2)^{3/2}}+C\)

    Exercise \(\PageIndex{20}\)

    \(\displaystyle\int{1\over t(9+4t^2)}\,dt\)

    Answer

    \(\dfrac{\ln\big|\sin\big(\arctan(2t/3)\big)\big|}{9}+C=\dfrac{1}{18}\left(\ln(4t^2)-\ln(9+4t^2)\right)+C\)

    Exercise \(\PageIndex{21}\)

    \(\displaystyle\int{\arctan 2t\over 1+4t^2}\,dt\)

    Answer

    \(\dfrac{1}{4}\big(\arctan(2t)\big)^2+C\)

    Exercise \(\PageIndex{22}\)

    \(\displaystyle\int {t\over t^2+2t-3}\,dt\)

    Answer

    \(\dfrac{3\ln\big|t+3\big|}{4}+\dfrac{\ln\big|t-1\big|}{4}+C\)

    Exercise \(\PageIndex{23}\)

    \(\displaystyle\int \sin^3 t\cos^4 t\,dt\)

    Answer

    \(\dfrac{\cos^7 t}{7}-\dfrac{\cos^5 t}{5}+C\)

    Exercise \(\PageIndex{24}\)

    \(\displaystyle\int{1\over t^2-6t+9}\,dt\)

    Answer

    \(\dfrac{1}{3-t}+C\)

    Exercise \(\PageIndex{25}\)

    \(\displaystyle\int{1\over t(\ln t)^2}\,dt\)

    Answer

    \(\dfrac{-1}{\ln t}+C\)

    Exercise \(\PageIndex{26}\)

    \(\displaystyle\int t(\ln t)^2\,dt\)

    Answer

    \(\dfrac{t^2(\ln t)^2}{2}-\dfrac{t^2\ln t}{2}+\dfrac{t^2}{4}+C\)

    Exercise \(\PageIndex{27}\)

    \(\displaystyle\int t^3e^{t}\,dt\)

    Answer

    \((t^3-3t^2+6t-6)e^t+C\)

    Exercise \(\PageIndex{28}\)

    \(\displaystyle\int{t+1\over t^2+t-1}\,dt\)

    Answer

    \(\dfrac{5-\sqrt{5}}{10}\ln\left(t+\dfrac{1+\sqrt{5}}{2}\right)+\dfrac{5+\sqrt{5}}{10}\ln\left(t+\dfrac{1-\sqrt{5}}{2}\right)+C\)


    This page titled 8.7: Additional exercises is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by David Guichard via source content that was edited to the style and standards of the LibreTexts platform.