Critical Points and Graphs of Differential Equations

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The discussion focuses on analyzing the differential equation dy/dt = alpha - y^2, specifically identifying critical points based on varying values of alpha. For alpha < 0, alpha = 0, and alpha > 0, the nature of the critical points changes, affecting their stability. The stability of each critical point is categorized as asymptotically stable, semistable, or unstable depending on the value of alpha. Additionally, for alpha > 0, the solution to the equation is derived, and a bifurcation diagram is suggested to visualize the critical points in relation to alpha. Participants are encouraged to share their attempts at solving the problem for targeted assistance.
nallapanther
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Consider the equation dy/dt = alpha - y^2

a) Find all of the critical points. How does it change as alpha < 0, alpha = 0 or alpha > 0?

b) In each case of different alphas, consider the graph of f(y) vs y and determine whether each critical point is asympototically stable, semistable, or unstable.

c) For alpha > 0, find the solution.

d) Plot a bifurcation diagram - this is a plot of the location of the critical points as a function of alpha (plot a graph alpha as x-axis and y-axis showing the location of the critical point)
 
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To get the best out of these forums, you should show us your attempt at the problem so we can target assistance to the place you most need it.

For example - do you know how the critical points of y are related to dy/dx ?
 
hey mate post up what you've done and i'll show you the next steps

the diff plots can be daunting in the beginning but if you keep practicing them they become very easy to interpret

let us know
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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