Let $f ( x , y ) = \tan ^ { - 1 } ( x / y )$

question 65

Multiple Choice

Let $f ( x , y ) = \tan ^ { - 1 } ( x / y )$ . Find the value of the partial derivative $f _ { y } ( 1,2 )$ .

• A) \(- 1\)
• B) \(- \frac { 1 } { 2 }\)
• C) \(- \frac { 1 } { 3 }\)
• D) \(- \frac { 1 } { 5 }\)
• E) \(\frac { 1 } { 5 }\)
• F) \(\frac { 1 } { 3 }\)
• G) \(\frac { 1 } { 2 }\)

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