U trokutu
vrijedi
i
.
Odredi kosinus kuta 
.
Let
be a triangle such that
and
.
Evaluate the cosine of .
[lang=hr]
U trokutu $ABC$ vrijedi $|BC|+|AC|=2|AB|$ i $\angle BAC - \angle CBA = 90 ^\circ$.
Odredi kosinus kuta $\angle ACB$.
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[lang=en]
Let $ABC$ be a triangle such that $|BC|+|AC|=2|AB|$ and $\angle BAC - \angle CBA = 90 ^\circ$.
Evaluate the cosine of $\angle ACB$.
[/lang]
