Recent content by HenryHallam

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    Undergrad Mapping a generic quadrilateral onto a rectangle (in 2 dimensions)

    Problem: I have a computer image of a grid "square" from an aviation chart. The "square" is actually approximately rectangular, but the left and right sides aren't quite parallel and the top and bottom sides are parallel but very slightly curved. I will assume/pretend that the top and...
  2. H

    Complex Number Proofs: Solving for z and z^-1 in a Cosine Equation

    Thanks for the assistance!
  3. H

    Is 0=x \sec ^2 x-5 a Function? A Look at Plotting and Simplifying

    I'm pretty confident that is true, but this isn't a function. You can say that 0=\frac{cos^2x}{x}-\frac{1}{5} implies and is implied by 0=x \sec ^2 x-5, but that does not mean the graph of y=\frac{cos^2x}{x}-\frac{1}{5} will be the same as the graph of y=x \sec ^2 x-5. The two graphs cross the...
  4. H

    Complex Number Proofs: Solving for z and z^-1 in a Cosine Equation

    Hi, I'm looking at a question from my Pure 6 textbook (united kingdom), it's not actually for homework but I'd like to figure it out. First part of the question goes like this: If 2 cos θ = z + z^-1 prove that (if n is a positive integer) 2 cos n θ = z^n + z^-n. I can get a...