If p+q+r=a+b+c=0, then the determinant ∣∣ ∣∣paqbrcqcrapbrbpcqa∣∣ ∣∣ equals.
If p + q + r = a + b + c = 0, then the determinant Δ=∣∣ ∣∣paqbrcqcrapbrbpcqa∣∣ ∣∣ equals