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projectiles question

Shox · 2007-03-31 17:16:17

could someone let me know how you get the 2 statements above from this diagram

31-03-2007 5:16pm

#1

Shox

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could someone let me know how you get the 2 statements above from this diagram

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Comments

#2 31-03-2007 7:05pm

ZorbaTehZ

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Maths Tables page 9,
Cos(A+B) rule and the Sin(A+B) rule i believe.

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#3 01-04-2007 4:44pm

cocoa

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well, using the formulae might work, but what seems easier (to me anyway) is to draw in a right angled triangle with angles 2B, 90-2B and 90. then it becomes clear (if you mark which side is hypoteneuse) that the sin of one angle is the cos of another.

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#4 01-04-2007 5:22pm

Delphi91

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The other way that I would look at it is that where two angles make up 90 degrees, the cos of one is equal to the sin of the other.

E.g. cos 30 = sin 60, sin 10 = cos 80, etc, etc.

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