Polar coordinates, maximum distance.

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SUMMARY

The discussion focuses on finding the maximum distance from the curve defined by the polar equation r=e^(θ) for 0≤θ≤(π/2) to the vertical line θ=(π/2), which corresponds to the y-axis (x=0). The key insight is that the distance to this line is represented by the x-coordinate, which can be expressed as x=r cos(θ). To maximize this distance, one must correctly interpret the polar coordinates and apply the transformation x=e^(θ)cos(θ).

PREREQUISITES
  • Understanding of polar coordinates and their conversion to Cartesian coordinates.
  • Familiarity with the polar equation r=e^(θ).
  • Knowledge of trigonometric functions, specifically cosine.
  • Ability to differentiate functions to find maxima.
NEXT STEPS
  • Study the conversion between polar and Cartesian coordinates in detail.
  • Learn how to differentiate polar equations to find maximum and minimum values.
  • Explore the properties of exponential functions in polar coordinates.
  • Practice problems involving distance calculations in polar coordinates.
USEFUL FOR

Students studying calculus, particularly those focusing on polar coordinates and optimization problems, as well as educators looking for examples of polar to Cartesian transformations.

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Homework Statement


The diagram (omitted) shows the curve C with polar equation r=e^(\theta), where 0\le\theta\le(pi/2). Find the maximum distance of a point of C from the line \theta=(pi/2), giving the answer in exact form.

The Attempt at a Solution



I'm not really sure how to attack this; it says in the examiners report that one needs to write x as e^(theta).cos(theta), but I can't see why this is...
 
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The line [itex]\theta= \pi/2[/itex] is just the vertical line x= 0, the y-axis and the distance from any point (x, y) to that line is just x. And, of course, [itex]x= r cos(\theta)[/itex]. That is what you want to maximize.
 
OMG I THOUGHT THE LINE WAS theta=pi/4 ... sigh...
 

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