MHB Calculating Radius of Circular Section from Sphere and Plane Intersection

Click For Summary
To find the radius of the circular section formed by the intersection of the sphere defined by x^2 + y^2 + z^2 = 49 and the plane 2x + 3y - z - 5√14 = 0, one approach is to calculate the distance from the sphere's center to the plane. This distance can be determined using the formula d = |Ax0 + By0 + Cz0 + D| / √(A^2 + B^2 + C^2). Once the distance d is found, the radius r of the circular section can be derived using the right triangle formed by the sphere's radius and the distance to the plane. This method simplifies the problem without needing to substitute z back into the sphere's equation. The final radius of the circular section can then be calculated effectively.
marutkpadhy
Messages
9
Reaction score
0
Find the radius of the circular section of the sphere of the sphere x^2 + y^2 + z^2 = 49 by the plane 2x+3y-z-5 \sqrt{14}= 0
 
Mathematics news on Phys.org
Suppose you solve the equation of the plane for $z$, and then substitute for $z$ into the equation of the sphere...what do you get?
 
View attachment 2708

I think it is easier to find the distance $d$ from the center of the sphere to the plane (recall the the distance from $(x_0,y_0,z_0)$ to $Ax+By+Cz+D=0$ is $\dfrac{Ax_0+By_y+Cz_0+D}{\sqrt{A^2+B^2+C^2}}$) and then find the radius $r$ of the required circular section from the right triangle.
 

Attachments

  • circle1.png
    circle1.png
    3.6 KB · Views: 89
I have been insisting to my statistics students that for probabilities, the rule is the number of significant figures is the number of digits past the leading zeros or leading nines. For example to give 4 significant figures for a probability: 0.000001234 and 0.99999991234 are the correct number of decimal places. That way the complementary probability can also be given to the same significant figures ( 0.999998766 and 0.00000008766 respectively). More generally if you have a value that...

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 11 ·
Replies
11
Views
7K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K