Calculus 3 : Calculus 3

Study concepts, example questions & explanations for Calculus 3

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Example Questions

Example Question #2921 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{xz}\\&\text{Where }f(x,y,z)=\frac{-{(ln{(3y)}sin{(3z)}e^{(x^2)})}}{5}\end{align*}

Possible Answers:

\displaystyle {\frac{{(12x^2cos{(3z)}ln{(3y)}^2sin{(3z)}e^{(2x^2)})}}{25}}

\displaystyle {\frac{-{(6xcos{(3z)}ln{(3y)}e^{(x^2)})}}{5}}

\displaystyle {-\frac{ {(3cos{(3z)}ln{(3y)}e^{(x^2)})}}{5} -\frac{ {(2xln{(3y)}sin{(3z)}e^{(x^2)})}}{5}}

\displaystyle {\frac{{(6xcos{(3z)}ln{(3y)}^2sin{(3z)}e^{(2x^2)})}}{25}}

Correct answer:

\displaystyle {\frac{-{(6xcos{(3z)}ln{(3y)}e^{(x^2)})}}{5}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[e^u]=e^udu\\&d[sin(u)]=cos(u)du\\&\text{Solve step-by-step:}\\&f(x,y,z)=\frac{-{(ln{(3y)}sin{(3z)}e^{(x^2)})}}{5}\\&f_{x}=\frac{-{(2xln{(3y)}sin{(3z)}e^{(x^2)})}}{5}\\&f_{xz}=\frac{-{(6xcos{(3z)}ln{(3y)}e^{(x^2)})}}{5}\end{align*}

Example Question #2922 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{zxz}\\&\text{Where }f(x,y,z)=\frac{-{(2\cdot3^{(3z)}cos{(y^2)}e^{(3x)})}}{7}\end{align*}

Possible Answers:

\displaystyle {\frac{-{(54\cdot3^{(3z)}cos{(y^2)}e^{(3x)}ln{(3)}^2)}}{7}}

\displaystyle {-\frac{ {(6\cdot3^{(3z)}cos{(y^2)}e^{(3x)})}}{7} -\frac{ {(12\cdot3^{(3z)}cos{(y^2)}e^{(3x)}ln{(3)})}}{7}}

\displaystyle {\frac{-{(5832\cdot3^{(9z)}cos{(y^2)}^3e^{(9x)}ln{(3)}^4)}}{343}}

\displaystyle {\frac{-{(216\cdot3^{(9z)}cos{(y^2)}^3e^{(9x)}ln{(3)}^2)}}{343}}

Correct answer:

\displaystyle {\frac{-{(54\cdot3^{(3z)}cos{(y^2)}e^{(3x)}ln{(3)}^2)}}{7}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[a^u]=a^uduln(a)\\&d[e^u]=e^udu\\&\text{Solve step-by-step:}\\&f(x,y,z)=\frac{-{(2\cdot3^{(3z)}cos{(y^2)}e^{(3x)})}}{7}\\&f_{z}=\frac{-{(6\cdot3^{(3z)}cos{(y^2)}e^{(3x)}ln{(3)})}}{7}\\&f_{zx}=\frac{-{(18\cdot3^{(3z)}cos{(y^2)}e^{(3x)}ln{(3)})}}{7}\\&f_{zxz}=\frac{-{(54\cdot3^{(3z)}cos{(y^2)}e^{(3x)}ln{(3)}^2)}}{7}\end{align*}

Example Question #2923 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{zx}\\&\text{Where }f(x,y,z)=\frac{-{(z^2e^{(x)})}}{{(4y^2)}}\end{align*}

Possible Answers:

\displaystyle {-\frac{ {(ze^{(x)})}}{{(2y^2)}} -\frac{ {(z^2e^{(x)})}}{{(4y^2)}}}

\displaystyle {\frac{{(z^3e^{(2x)})}}{{(8y^4)}}}

\displaystyle {\frac{-{(ze^{(x)})}}{{(2y^2)}}}

\displaystyle {\frac{{(z^2e^{(2x)})}}{{(4y^4)}}}

Correct answer:

\displaystyle {\frac{-{(ze^{(x)})}}{{(2y^2)}}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[e^u]=e^udu\\&\text{Solve step-by-step:}\\&f(x,y,z)=\frac{-{(z^2e^{(x)})}}{{(4y^2)}}\\&f_{z}=\frac{-{(ze^{(x)})}}{{(2y^2)}}\\&f_{zx}=\frac{-{(ze^{(x)})}}{{(2y^2)}}\end{align*}

Example Question #2924 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{zxz}\\&\text{Where }f(x,y,z)=2\cdot3^{(3x)}y^2cos{(z)}\end{align*}

Possible Answers:

\displaystyle {-72\cdot3^{(9x)}y^6ln{(3)}^2cos{(z)}sin{(z)}^2}

\displaystyle {-6\cdot3^{(3x)}y^2ln{(3)}cos{(z)}}

\displaystyle {6\cdot3^{(3x)}y^2ln{(3)}cos{(z)} - 4\cdot3^{(3x)}y^2sin{(z)}}

\displaystyle {24\cdot3^{(9x)}y^6ln{(3)}cos{(z)}sin{(z)}^2}

Correct answer:

\displaystyle {-6\cdot3^{(3x)}y^2ln{(3)}cos{(z)}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[cos(u)]=-sin(u)du\\&d[a^u]=a^uduln(a)\\&d[sin(u)]=cos(u)du\\&\text{Solve step-by-step:}\\&f(x,y,z)=2\cdot3^{(3x)}y^2cos{(z)}\\&f_{z}=-2\cdot3^{(3x)}y^2sin{(z)}\\&f_{zx}=-6\cdot3^{(3x)}y^2ln{(3)}sin{(z)}\\&f_{zxz}=-6\cdot3^{(3x)}y^2ln{(3)}cos{(z)}\end{align*}

Example Question #2925 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{zxyy}\\&\text{Where }f(x,y,z)=\frac{-{(2y^2sin{(3z)}sin{(x)})}}{5}\end{align*}

Possible Answers:

\displaystyle {\frac{{(192y^6cos{(3z)}sin{(3z)}^3cos{(x)}sin{(x)}^3)}}{625}}

\displaystyle {\frac{-{(12cos{(3z)}cos{(x)})}}{5}}

\displaystyle {-\frac{ {(8ysin{(3z)}sin{(x)})}}{5} -\frac{ {(6y^2cos{(3z)}sin{(x)})}}{5} -\frac{ {(2y^2sin{(3z)}cos{(x)})}}{5}}

\displaystyle {\frac{{(5184y^5cos{(3z)}^4cos{(x)}^3sin{(x)})}}{625}}

Correct answer:

\displaystyle {\frac{-{(12cos{(3z)}cos{(x)})}}{5}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[sin(u)]=cos(u)du\\&\text{Solve step-by-step:}\\&f(x,y,z)=\frac{-{(2y^2sin{(3z)}sin{(x)})}}{5}\\&f_{z}=\frac{-{(6y^2cos{(3z)}sin{(x)})}}{5}\\&f_{zx}=\frac{-{(6y^2cos{(3z)}cos{(x)})}}{5}\\&f_{zxy}=\frac{-{(12ycos{(3z)}cos{(x)})}}{5}\\&f_{zxyy}=\frac{-{(12cos{(3z)}cos{(x)})}}{5}\end{align*}

Example Question #2926 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{yzy}\\&\text{Where }f(x,y,z)=-2sin{(z^2)}e^{(3y)}ln{(x)}\end{align*}

Possible Answers:

\displaystyle {-2592z^2cos{(z^2)}^2sin{(z^2)}e^{(9y)}ln{(x)}^3}

\displaystyle {-36zcos{(z^2)}e^{(3y)}ln{(x)}}

\displaystyle {- 12sin{(z^2)}e^{(3y)}ln{(x)} - 4zcos{(z^2)}e^{(3y)}ln{(x)}}

\displaystyle {-144zcos{(z^2)}sin{(z^2)}^2e^{(9y)}ln{(x)}^3}

Correct answer:

\displaystyle {-36zcos{(z^2)}e^{(3y)}ln{(x)}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[e^u]=e^udu\\&d[sin(u)]=cos(u)du\\&\text{Solve step-by-step:}\\&f(x,y,z)=-2sin{(z^2)}e^{(3y)}ln{(x)}\\&f_{y}=-6sin{(z^2)}e^{(3y)}ln{(x)}\\&f_{yz}=-12zcos{(z^2)}e^{(3y)}ln{(x)}\\&f_{yzy}=-36zcos{(z^2)}e^{(3y)}ln{(x)}\end{align*}

Example Question #2927 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{zzxx}\\&\text{Where }f(x,y,z)=-z^2ln{(4x)}sin{(y)}\end{align*}

Possible Answers:

\displaystyle {\frac{{(4z^6ln{(4x)}^2sin{(y)}^4)}}{x^2}}

\displaystyle {- 4zln{(4x)}sin{(y)} -\frac{ {(2z^2sin{(y)})}}{x}}

\displaystyle {\frac{-{(16zln{(4x)}^2sin{(y)}^4)}}{x^3}}

\displaystyle {\frac{{(2sin{(y)})}}{x^2}}

Correct answer:

\displaystyle {\frac{{(2sin{(y)})}}{x^2}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[ln(u)]=\frac{du}{u}\\&\text{Solve step-by-step:}\\&f(x,y,z)=-z^2ln{(4x)}sin{(y)}\\&f_{z}=-2zln{(4x)}sin{(y)}\\&f_{zz}=-2ln{(4x)}sin{(y)}\\&f_{zzx}=\frac{-{(2sin{(y)})}}{x}\\&f_{zzxx}=\frac{{(2sin{(y)})}}{x^2}\end{align*}

Example Question #2928 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{xyx}\\&\text{Where }f(x,y,z)=\frac{{(y^2cos{(3x)}ln{(z)})}}{3}\end{align*}

Possible Answers:

\displaystyle {-6ycos{(3x)}ln{(z)}}

\displaystyle {\frac{{(2ycos{(3x)}ln{(z)})}}{3} - 2y^2sin{(3x)}ln{(z)}}

\displaystyle {-12y^4cos{(3x)}sin{(3x)}^2ln{(z)}^3}

\displaystyle {\frac{{(2y^5cos{(3x)}sin{(3x)}^2ln{(z)}^3)}}{3}}

Correct answer:

\displaystyle {-6ycos{(3x)}ln{(z)}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[cos(u)]=-sin(u)du\\&d[sin(u)]=cos(u)du\\&\text{Solve step-by-step:}\\&f(x,y,z)=\frac{{(y^2cos{(3x)}ln{(z)})}}{3}\\&f_{x}=-y^2sin{(3x)}ln{(z)}\\&f_{xy}=-2ysin{(3x)}ln{(z)}\\&f_{xyx}=-6ycos{(3x)}ln{(z)}\end{align*}

Example Question #2929 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{xxy}\\&\text{Where }f(x,y,z)=\frac{{(2cos{(4y)}sin{(z^2)})}}{{(5x)}}\end{align*}

Possible Answers:

\displaystyle {\frac{-{(32cos{(4y)}^2sin{(4y)}sin{(z^2)}^3)}}{{(125x^5)}}}

\displaystyle {-\frac{ {(4cos{(4y)}sin{(z^2)})}}{{(5x^2)}} -\frac{ {(8sin{(4y)}sin{(z^2)})}}{{(5x)}}}

\displaystyle {\frac{{(128cos{(4y)}^2sin{(4y)}sin{(z^2)}^3)}}{{(125x^8)}}}

\displaystyle {\frac{-{(16sin{(4y)}sin{(z^2)})}}{{(5x^3)}}}

Correct answer:

\displaystyle {\frac{-{(16sin{(4y)}sin{(z^2)})}}{{(5x^3)}}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[cos(u)]=-sin(u)du\\&\text{Solve step-by-step:}\\&f(x,y,z)=\frac{{(2cos{(4y)}sin{(z^2)})}}{{(5x)}}\\&f_{x}=\frac{-{(2cos{(4y)}sin{(z^2)})}}{{(5x^2)}}\\&f_{xx}=\frac{{(4cos{(4y)}sin{(z^2)})}}{{(5x^3)}}\\&f_{xxy}=\frac{-{(16sin{(4y)}sin{(z^2)})}}{{(5x^3)}}\end{align*}

Example Question #2930 : Calculus 3

\displaystyle \begin{align*}&\text{Perform the partial derivation, }f_{zz}\\&\text{Where }f(x,y,z)=\frac{{(2\cdot4^{(4z)}y^2sin{(x^2)})}}{5}\end{align*}

Possible Answers:

\displaystyle {\frac{{(64\cdot4^{(8z)}y^4sin{(x^2)}^2ln{(4)}^2)}}{25}}

\displaystyle {\frac{{(32\cdot4^{(4z)}y^2sin{(x^2)}ln{(4)}^2)}}{5}}

\displaystyle {\frac{{(256\cdot4^{(8z)}y^4sin{(x^2)}^2ln{(4)}^3)}}{25}}

\displaystyle {\frac{{(16\cdot4^{(4z)}y^2sin{(x^2)}ln{(4)})}}{5}}

Correct answer:

\displaystyle {\frac{{(32\cdot4^{(4z)}y^2sin{(x^2)}ln{(4)}^2)}}{5}}

Explanation:

\displaystyle \begin{align*}&\text{When taking partial derivatives, order does not matter; you can}\\&\text{simply treat any variable that you're not deriving the equation for as constant.}\\&\text{Utilizing derivative rules:}\\&d[uv]=udv+vdu\\&(f\circ g )'=(f'\circ g )\cdot g'\\&d[a^u]=a^uduln(a)\\&\text{Solve step-by-step:}\\&f(x,y,z)=\frac{{(2\cdot4^{(4z)}y^2sin{(x^2)})}}{5}\\&f_{z}=\frac{{(8\cdot4^{(4z)}y^2sin{(x^2)}ln{(4)})}}{5}\\&f_{zz}=\frac{{(32\cdot4^{(4z)}y^2sin{(x^2)}ln{(4)}^2)}}{5}\end{align*}

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