Question

Find the slope of the tangent line to the curve
2x^2+4xy+2y^3=114 at the point (-7,4)

Answer 1

@SolomonZelman

Answer 2

do you know how to take the derivative of a function?

Answer 3

when x = 0 y = 2Y^3 = 114 so y^3 = 57 y = 57^1/3 = 3.84
when y = 0 2x^2 = 114 x^2 = 57 x = + and - 57^1/2 = 7.55

Answer 4

split the original into an x function and a y function

Answer 5

@jim_thompson5910 what is the correct way to do this problem?

Answer 6

you have to use implicit differentiation here

Answer 7

here's a page on implicit differentiation

http://www.sosmath.com/calculus/diff/der05/der05.html

you basically derive both sides with respect to x

Answer 8

so it's x and y as a function of x ?

thanks

Answer 9

yes that's correct, y = f(x)

Answer 10

thanks for all your help

Answer 11

i did implicit differentiation and got dy/dx= (4x-y-1)/x+9y^2
and it said its wrong, what did i do wrong?