[Giúp] Toán nâng cao!!!

B

braga

$$VT-VP=\dfrac{a^{2}}{4}+b^{2}+c^{2}-ab-bc+2bc+\dfrac{a^{2}}{12}=\left(\dfrac{a}{2}-b-c\right)^{2}+\dfrac{a^{2}-36bc}{12}>0$$
 
Top Bottom