1)in a triangle, if A=2B prove that a^2=b^2 + bc

2)in a triangle, if a+c=2b prove that cot(C/2) = 3 tan(A/2)

PS please dont use calculus to solve!

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- Jun 17th 2007, 11:24 PM #1

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- Jun 18th 2007, 03:42 AM #2
In general there is a difference between the variables "b" and "B." When referring to triangles B tends to represent the angle across from the side of length b. The first question, with $\displaystyle a^2 = B^2 + bc$ then, makes no sense. Even if you meant b = B, there are a variety of triangles with the property $\displaystyle A = 2B$ with different values of c so the proposed equality need not be true.

-Dan

- Jun 18th 2007, 09:33 AM #3

- Jun 19th 2007, 02:01 AM #4

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