Misc 6 - Chapter 4 Class 12 Determinants
Last updated at Dec. 16, 2024 by Teachoo
Whole row/column one
Last updated at Dec. 16, 2024 by Teachoo
Misc 6 Evaluate |■8(1&x&y@1&x+y&y@1&x&x+y)| |■8(1&x&y@1&x+y&y@1&x&x+y)| Applying R1→ R1 – R2 = |■8(𝟏−𝟏&x−x−y&y@1&x+y&y@1&𝑥&x+y)| = |■8(𝟎&−y&y@1&x+y&y@1&𝑥&x+y)| Applying R2→ R2 – R3 = |■8(0&−y&0@𝟏−𝟏&x+y−x&y−x−y@1&x&x+y)| = |■8(0&−y&0@𝟎&y&−x@1&𝑥&x+y)| Expanding determinant along C1 = 0 |■8(𝑦&−𝑥@𝑥&𝑥+𝑦)| – 0 |■8(−𝑦&𝑦@𝑥&𝑥+𝑦)| + 1 |■8(−𝑦&0@𝑦&−𝑥)| = 0 – 0 + 1 |■8(−𝑦&0@𝑦&−𝑥)| = (0 – 0 + 1(xy)) = xy