Find the partial derivative $f _ { y } \text { for the function } f ( x , y ) = x ^ { 2 } - 2 y ^ { 2 } + 7$
A) $f _ { y } ( x , y ) = - 8 y$
B) $f _ { y } ( x , y ) = - 5 y$
C) $f _ { y } ( x , y ) = 9 y$
D) $f _ { y } ( x , y ) = - 4 y$
E) $f _ { y } ( x , y ) = 10 y$

Question

Find the partial derivative $f _ { y } \text { for the function } f ( x , y ) = x ^ { 2 } - 2 y ^ { 2 } + 7$ 
A) $f _ { y } ( x , y ) = - 8 y$
B) $f _ { y } ( x , y ) = - 5 y$
C) $f _ { y } ( x , y ) = 9 y$
D) $f _ { y } ( x , y ) = - 4 y$
E) $f _ { y } ( x , y ) = 10 y$

Quizplus · Accepted Answer

Taking the partial derivative of the function with respect to y, we treat x as a constant and obtain:
$$
f_y(x,y) = -4y
$$
Therefore, the correct answer is (D).

Find the Partial Derivative fy for the function f(x,y)=x2−2y2+7f _ { y } \text { for the function } f ( x , y ) = x ^ { 2 } - 2 y ^ { 2 } + 7fy​ for the function f(x,y)=x2−2y2+7

Find the Partial Derivative $f _ { y } \text { for the function } f ( x , y ) = x ^ { 2 } - 2 y ^ { 2 } + 7$