Find the requested function and sketch the curve

  • Context: Undergrad 
  • Thread starter Thread starter BrendanM
  • Start date Start date
  • Tags Tags
    Curve Function Sketch
Click For Summary
SUMMARY

The discussion focuses on calculating the surface area of a sphere as a function of time, given that the radius expands at a rate of 1 meter per minute, starting from a radius of 1 meter. The formula for surface area is A = 4πr², and the rate of change of surface area is derived as dA/dt = 8πr. The correct function for surface area over time is A(t) = 4π + 8πt, with the curve starting at the point (0, 4π) and increasing linearly. The x-axis represents time (t), while the y-axis represents surface area (A).

PREREQUISITES
  • Understanding of calculus, specifically derivatives
  • Familiarity with the formula for the surface area of a sphere
  • Basic knowledge of graphing linear functions
  • Ability to manipulate algebraic expressions
NEXT STEPS
  • Learn about the derivative of functions in calculus
  • Study the properties of linear functions and their graphs
  • Explore the relationship between radius and surface area in three-dimensional geometry
  • Practice sketching curves based on derived functions
USEFUL FOR

Students studying calculus, educators teaching geometry, and anyone interested in understanding the dynamics of geometric shapes and their properties over time.

BrendanM
Messages
17
Reaction score
0
help me please!

Im very rusty here's my problem, please help thanks!

The radius of a sphere is expanding at the rate of 1 meter/min. At t=0 the radius is 1. In earch case, find the requested function and sketch the curve.

a)The surface area of the sphere as a function of the time;
For this i took: dR/dt = 1 m/min
A=4*Pi*r^2
dA/dt=8*pi*r*dR/dt
dA/dt = 8*pi*r <--- if this is right how do i sketch this graph as a function of time??
my graph points that i ploted were (0,8pi),(1,16pi),(2,24pi) etc... but this is confusing me because at t=0 radius is 1... is my x-axis supposed to be time or radius someone help me I am confused..
 
Physics news on Phys.org
Write r as a function of time then plot:
[tex]r = 1 + t[/tex]
 


The requested function in this case is the surface area of the sphere as a function of time, which can be represented as A(t). The curve that would be sketched would be a linear curve, as the rate of change of the surface area is constant (8*pi*r). The x-axis would represent time (t) and the y-axis would represent surface area (A).

To sketch the curve, we can plot the points you have calculated: (0, 8*pi), (1, 16*pi), (2, 24*pi), etc. These points represent the surface area at different points in time. We can then connect these points with a straight line to create the linear curve.

However, as you mentioned, the radius at t=0 is 1, which means the surface area at t=0 would be 4*pi*1^2 = 4*pi. This means the first point on the graph should be (0, 4*pi) instead of (0, 8*pi). This will result in a curve that starts at (0, 4*pi) and increases linearly from there.

In summary, the requested function and curve for this problem would be:
A(t) = 4*pi + 8*pi*t
Curve: a linear curve starting at (0, 4*pi) and increasing at a constant rate of 8*pi.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
1
Views
4K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K