C-03-Q032mediumsingle_mcqWith the same notation, f2=f^2 =f2=a2(b2+c2)−a24\dfrac{2(b^2+c^2) - a^2}{4}42(b2+c2)−ab2(a2+c2)−b24\dfrac{2(a^2+c^2) - b^2}{4}42(a2+c2)−c2(a2+b2)−c24\dfrac{2(a^2+b^2) - c^2}{4}42(a2+b2)−da2+b2+c24\dfrac{a^2+b^2+c^2}{4}4a2+b2+c