Question

If 4x2+3x+xy=2 and y(2)=–10 , find y'(2) by implicit differentiation.

i keep getting the wrong answer for this problem evn when plugging 2 in for y.

Answer 1

d/dx(4x^2+3x+xy)=d/dx(2)
8x+3+y+xy'=0
At x=2, y=-10, we get
16+3-10+2y'=0
Solving for y' yields y'(2)=-9/2.

You are not suppose to plug in 2 for y. y(2)=-10 means that the function has a value of -10 when x=2.

Answer 2

OMG this helped soooo much!!! thank you!!!