# Partial differentiation help!!!Watch

#1
Question B10

I've worked out part i and got the following answers:

dw/dx = 4x-y+1

dw/dy = -2y-x-z

dw/dz = 6z-y

I can't do part ii, I'm unable to get the values of a,b and c

Can anyone help?
0
8 years ago
#2
You just have to solve the system 4x-y+1=0, -2y-x-z=0, 6z-y=0.
0
#3
I've tried to do that but I keep getting the wrong answer.
0
8 years ago
#4
(Original post by bio_ray18)
I've tried to do that but I keep getting the wrong answer.
0
#5
my final answer is (11/50, -6/50, 1/50)

which when substituted back in gives the wrong solution.
0
8 years ago
#6
(Original post by bio_ray18)
my final answer is (11/50, -6/50, 1/50)

which when substituted back in gives the wrong solution.
So post your working or just keep trying.
0
#7
dw/dx= 4x-y+1

dw/dy= -2y-x-z

dw/dz= 6z-y

equating them all to zero:
4x-y+1= 0

-2y-x-z= 0

6z-y=0
y=6z

substituting y into the first 2 equations doesnt give correct answers for x and y.
0
8 years ago
#8
(Original post by bio_ray18)
6z-y=0
y=-6z
#9
(Original post by ghostwalker)
I've adjusted that, but it still doesn't work.
0
8 years ago
#10
(Original post by bio_ray18)
I've adjusted that, but it still doesn't work.
That is not a helpful comment. Clarify.
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