Sketch the region enclosed by the graphs of x = 0, 6y – 5x = 0, and x + 3y = 21.

Find the area.

Find the volume of the solid formed when the region is revolved around the y-axis.

Question

Sketch the region enclosed by the graphs of x = 0, 6y – 5x = 0, and x + 3y = 21.

Find the area.  

Find the volume of the solid formed when the region is revolved around the y-axis.

anonymous · Answer

x=0  --> this is the equation for y-axis
6y-5x = 0  --> this is a straight line (choose two points and draw a line throught hem)
x+3y=21 --> another straight line.

anonymous · Answer

|dw:1367079712822:dw|

anonymous · Answer

21 units^2
263.89 units^3 

Are these right? ^

anonymous · Answer

area is correct.

anonymous · Answer

volume bye disc method:
$$
V=\pi\int_{y=0}^5\left({5\over 6}y\right)^2dy+\pi\int_5^7(21-3y)^2dy
$$

anonymous · Answer

attachment

anonymous · Answer

thats what you got?

anonymous · Answer

Yeah. Am I right? The first is okay, but what about the second?

anonymous · Answer

is that the integral you solved?

anonymous · Answer

what method did you use?
shell, disc, washer, ????

anonymous · Answer

Find the volume of the solid formed when the region is revolved around the y-axis.
263.89 units^3  
I just wanna know if that is right as well ^

anonymous · Answer

and I wanna know what formula you used