Change from rectangular to cylindrical coordinates. (Let r\geq0 and 0\leq\theta\leq2\pi.) a) (-2, 2, 2) b) (-9,9\sqrt{3,6}) c) Use cylindrical coordin

coexpennan

coexpennan

Answered question

2021-06-09

Change from rectangular to cylindrical coordinates. (Let r0 and 0θ2π.)
a) (2,2,2)
b) (9,93,6)
c) Use cylindrical coordinates.
Evaluate
ExdV
where E is enclosed by the planes z=0 and
z=x+y+10
and by the cylinders
x2+y2=16 and x2+y2=36
d) Use cylindrical coordinates.
Find the volume of the solid that is enclosed by the cone
z=x2+y2
and the sphere
x2+y2+z2=8.

Answer & Explanation

wornoutwomanC

wornoutwomanC

Skilled2021-06-10Added 81 answers

Step 1 
Convert coordinates from rectangular to cylindrical.
Let r0 and 0θ2π 
a) (x,y,z)=(2,2,2) 
Use cylindrical coordinates. 
r=x2+y2=(2)3+23=22 
θ=arctan(yx)=arctan(22)(1)=3π4 
z=z=2 
Consequently, the necessary coordinates are,
(r,θ,z)=(22,2π4,2) 
Step 2 
b) (x,y,z)=(9.93.6) 
Use cylindrical coordinates. 
r=x2+y2=(9)2+(93)2=18 
θ=arctan(yx)=arctan(939)=arctan(3)=2π3 
z=z=6 
Therefore, the required coordinates is, 
(r,θ,z)=(18,2π3,6) 
Step 3 
c) Use cylindrical coordinates, to evaluate ExdV 
Where E is enclosed by the planes z=0 and z=x+y+10 and by the cylinders x2+y2=16 and x2+y2=36 
16x2+y236 
16r236 As x2+y2=r2 
4r6 
and 0θ2π 
and 0zx+y+10 
0zrcosθ+rsinθ+10 As x=rcosθ,y=rsinθ 
and dV=dxdydz=rdrdθdz 
So, ExdV=02a460rcosθ+rsinθ+10rcosθ(rdrdθdz) 
=02π460rcosθ+rsinθ+10r2cosθdrdθdz 
=02π46r2(rcosθ+rsinθ+10)cosθdrdθ 
=02π46(r3(cos2θ+sinθcosθ)+10r2cosθ)drdθ 
 

Do you have a similar question?

Recalculate according to your conditions!

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?