- #1

utkarshakash

Gold Member

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## Homework Statement

In triangle ABC with A as obtuse angle, AD and AE are median and altitude respectively. If BAD = DAE=EAC, then sin^3(A/3)cos(A/3) equals

## Homework Equations

## The Attempt at a Solution

CE = a/2. Let DE = x. Then BD = a/2 - x.

Let AE = p, AD = q.

For ΔADB

[itex]\cos \frac{A}{3} = \dfrac{q^2+c^2-(a/2 -x)^2}{2cq}[/itex]

I can also write cos A/3 for other two triangles using the same approach but I don't know which one to use in the final expression. Also it will contain p and q which is unknown. I have no idea what sin(A/3) would be. This seems really complicated.