Advanced Math practice question

Answer: -2

(a + b + c)² = a² + b² + c² + 2(ab + bc + ca) = 0, so a² + b² + c² = −2(ab + bc + ca), and the ratio is −2.

Common wrong answers

If you answered 0

0 would need a² + b² + c² = 0, which forces a = b = c = 0 and makes the denominator zero.

If you answered 2

2 has the wrong sign.

If you answered -1

−1 forgets the factor 2 in the expansion.

More Advanced Math questions

• Very hard
  The function f(x) = x² + 6x + 5 is rewritten in the form f(x) = (x + a)² + b. What is the value of b?
• Very hard
  What is the solution to the equation 6/(x − 2) = 3?
• Very hard
  The polynomial p(x) = x³ − 4x has how many distinct real zeros?
• Very hard
  The polynomial p is defined by p(x) = x³ + ax² + bx − 12, where a and b are constants. If x − 2 is a factor of…
• Very hard
  The function f, defined by f(x) = 3000(1.331)^(x/12), gives the value, in dollars, of an investment x months a…
• Very hard
  In the xy-plane, the parabola y = x² − 4x + 7 and the line y = mx − 2, where m is a constant, intersect at exa…