Standard +0.3 This is a straightforward implicit differentiation question requiring product rule and chain rule application, followed by substitution of given coordinates. While it involves multiple differentiation techniques, it's a standard textbook exercise with no novel problem-solving required, making it slightly easier than average.
2 A curve has equation $x ^ { 2 } \ln y + y ^ { 2 } + 4 x = 9$.\\
Find the gradient of the curve at the point $( 2,1 )$.\\
\hfill \mbox{\textit{CAIE P2 2024 Q2 [5]}}