tìm GTLN,GTNN

\(\dfrac{2x+1}{x^2+2}\)

\(tìmxthuộczđể\)

\(\dfrac{x^5+3x^3+x^2+3x-7}{x^2+2}cóGTnguyên\)

cho tam giác ABC có

BC = a

AC = b

AB = c

biết \(\dfrac{ab}{b+c}+\dfrac{bc}{c+d}+\dfrac{ca}{a+b}=\dfrac{ca}{b+c}+\dfrac{ab}{c+a}+\dfrac{bc}{a+b}\)

cmr tam giác ABC cân

@Akai Haruma @phynit