Question

implicit differentiation y^2 +4xy +x^2 = 13... i need to know how the 4xy gets differentiated with product rule

Answer 1

y^2 + 4xy + x^2 = 13

f^2(x) + 4x f(x) + x^2 = 13

2f(x)f′(x)+4(f(x)+xf′(x))+2x=0

more easiliy written as

2yy′=4(y+xy′)+2x=0