In triangle ABC, AB=3, AC=6, BC=8, and D lies on BC such that AD bisects \(\angle BAC\). Find \(\cos \angle BAD\)
In triangle ABC, AB= c = 3, AC= b = 6, BC= a = 8, and D lies on BC such that AD bisects \(\angle BAC \). Find \(\cos\angle BAC=cos( \alpha) \)
\(cosine:\\ a^2=b^2+c^2-2bc\cdot cos(\alpha)\\ cos(\alpha)= \frac{b^2+c^2-a^2}{2bc}=\frac{36+9-64}{2\cdot 6\cdot 3}\)
\(cos(\alpha)= \cos\angle BAC=-0,52\overline 7\)
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