Law of Cosines and to Find Extremum by Completing Square
In $ \displaystyle \Delta ABC$, $ \displaystyle AB=(5-x)$ cm, $ \displaystyle BC=(4+x)$ cm, $ \dis…
In $ \displaystyle \Delta ABC$, $ \displaystyle AB=(5-x)$ cm, $ \displaystyle BC=(4+x)$ cm, $ \dis…