Alan

None of the other sections works properly as far as I can tell!

You can do some vector/matrix calculations in Scientific mode though.  For example:

Output:

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!!!  Strange calculator.  

9/343 = 0.026239...

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If you are talking about a right triangle then the angle is given by  arctan(opposite/adjacent)

Definitions:

hyperbolic sine:   sinh(x) = (e^x - e^-x)/2    (pronounced shine!)

hyperbolic cosine:  cosh(x) = (e^x + e^-x)/2

hyperbolic tangent:   tanh(x) = (e^x - e^-x)/(e^x + e^-x)   (pronounced tansh!)

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a²-36  

This is a standard difference of two squares so: a² - 36 → a² - 6² →  (a+6)(a-6)

b²+5b+6  →  (b + 2)(b + 3)

7(x-1)-x(x+1) doesn't factor nicely at all as far as I can see! 

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I assume you want to solve for t.

You need a numerical method.  Simple iteration will do:

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I guess it's just related to the fact that the integral is defined in terms of the limit of a sum of infinitely small segments.

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I've never looked into the theory behind it Melody!  Perhaps I should do so.

Type the determinant function in by hand as follows:

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Then press = or Enter

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The other one:

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