Volume of Region Bounded by Given Planes

[alalall2]

Homework Statement

(1 pt) Find the volume of the region bounded by the planes

Homework Equations

V = ∫∫7/4-6/4y-2/4x

The Attempt at a Solution

Since y=x I found their values when z = 0.
6x+2x=7, x=7/8
y= 7/8 is the maximum value y will have in this integration as it decreases as x approaches its maximum value: 2x = 7, x=7/2.

When I made a 2-D image of the region I would be integrating on I came up with a triangle which had two areas that needed to be integrated separately as in the first region: 0≤x≤7/8 and 0≤y≤x, and in the second region: 7/8≤x≤7/2 and 0≤y≤(7/6 - x/3).

After integrating my result was 0.893229167.

What I am wondering is if I am using the correct limits for my integration or if I made a mistake in my math.

 

[wywong]

I would avoid double integral thus: a horizontal cross-section of the region is bounded by the x and y axes and the line

2x+6y = 7-4z

The area of that right angle triangle is \frac{(7-4z)^2}{24} for z in[0,\frac{7}{4}].

The definite integral should be \frac{7^3}{12\cdot 24}=1.19

 

[alalall2]

The system still thinks that is an incorrect answer

 

[wywong]

Could the system be expecting a different format than what you entered, such as different number of decimal places?