Alan

See my edit above.

NaN (Not A Number) is commonly used in many computer languages to represent an undefined region of a function.

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You can put limits on as follows.  In the Input bar type:  If(-3<x<2,x^2,NaN) 

This results in:

(I changed the colour myself - the default is black).

I should note:

1. The If statement is in the form If(condition, result if condition is true, result if condition is false);

2. NaN stands for Not A Number.

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Right method zac, but 0.001m is 1mm not 10mm.

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Melody, You use the "Input" line below the graph.  Just type in y=x^2-4*x and press Enter.  Similarly for x=4.

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n = 51

$${\left(-{\mathtt{1}}\right)}^{{\mathtt{51}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{1}}{\mathtt{\,\times\,}}{\mathtt{51}} = {\mathtt{50}}$$

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Take logs of both sides and use the fact that log(a^b) = b*log(a):

x*ln(2) = (x-9)*ln(9)

9*ln(9) = x*(ln(9) - ln(2))

x = 9*ln(9)/(ln(9) - ln(2))

$${\mathtt{x}} = {\frac{{\mathtt{9}}{\mathtt{\,\times\,}}{ln}{\left({\mathtt{9}}\right)}}{\left({ln}{\left({\mathtt{9}}\right)}{\mathtt{\,-\,}}{ln}{\left({\mathtt{2}}\right)}\right)}} \Rightarrow {\mathtt{x}} = {\mathtt{13.147\: \!608\: \!785\: \!565\: \!331\: \!8}}$$

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There is something odd about the diagram.

$$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sin}}{\left({\mathtt{72}}^\circ\right)} = {\mathtt{0.951\: \!056\: \!516\: \!295}}$$

$${\frac{{\mathtt{6}}}{{\mathtt{15}}}} = {\frac{{\mathtt{2}}}{{\mathtt{5}}}} = {\mathtt{0.4}}$$

!!!

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1.1875 → 11875/10000 → 19/16

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Annie:   300

Bobby:  280

Ciro:     280

Denise: 280.1

Sum = 1140.1

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Melody, it is the "mg" vector that constitutes the hypotenuse of the right-angled triangle, not the  "mgsinα" line  (I didn't attempt to draw the two magnitudes to scale; I probably should have done!).

To convince yourself that the component along the slope is mgsinα think of the limit when α = 0.  The component along the "slope" must then be zero.

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