Problem: For integers a,ba, ba,b and ccc, define a,b,c\boxed{a, b, c}a,b,c​ to mean ab−bc+caa^{b}-b^{c}+c^{a}ab−bc+ca. Then 1,−1,2\boxed{1,-1,2}1,−1,2​ equals
Answer Choices:
A. −4-4−4
B. −2-2−2
C. 000
D. 222
E. 444
Solution:
1,−1,2=1−1−(−1)2+21=1−1+2=2\boxed{1,-1,2}=1^{-1}-(-1)^{2}+2^{1}=1-1+2=21,−1,2​=1−1−(−1)2+21=1−1+2=2.