Question

Use implicit differentiation to find an equation of the tangent line to the ellipse at the given point. (2,4)
(x^2/4)+(y^2/8)=3
i got the equation to use -2x/y
and then the equation after plugging in i got
(y-4)=-1(x-2)
not sure why thats wrong

Answer 1

2/4 x + 2/8 y y' = 0

x/2 + y y'/4 = 0

y y'/4 = -x/2

y y' = -2x

y' = -2x/y is good

Answer 2

you didnt provide a point but lets use (a,b)

the slope of the tangent line is -2a/b so we can use the point slope formula

Answer 3

y = -2a(x-a)/b + b

Answer 4

oh sorry the point is (2,4)

Answer 5

i plug into the formula you gave me but says still wrong

Answer 6

then there is something about the format that it is not liking. can you post a picture of the problem to verify you have posted the correct information?

Answer 7

cant i just tell you what answer i got dont really have a camera on me

Answer 8

is it on your screen? or on paper?

Answer 9

and the info i posted is correct checked it twice

Answer 10

when i work with a program like mathlab, i tend to read over some instructions that ask for a sepcific formating which is why i was wondering

Answer 11

nope theres no asking for any type of formatting this is webassign they dont write on there in what form they want my professor told us to try the form i wrote out or slope intercept

Answer 12

y = -(x-2) + 4

y = -x+6

Answer 13

you may want to consult webassign to find out if there any IT issues or something.
if its consistently not allowing you to submit correct answers, thats not good

Answer 14

alot of students complain about i but some reason even though its Purdue they wont take time to fix it have no idea why

Answer 15

they give us 3 tries though because of the reason it takes correct answers it just has to be the form they wont they just dont ever post what form they want

Answer 16

your process and outcome were correct, so good luck with the formatting issues

Answer 17

lol thanks