NTA Abhyas JEE Main2020MathematicsDeterminantsPractice
If Δ r = 2 r - 1 m C r 1 m 2 - 1 2 m m + 1 sin 2 m 2 sin 2 m sin 2 m + 1 , then the value of ∑ r = 0 m Δ is
Options
- A1
- B3
- C2
- D0
Correct answer
D. 0
Step-by-step solution
Δ r = 2 r - 1 m C r 1 m 2 - 1 2 m m + 1 s i n 2 m 2 sin 2 m sin 2 m + 1 ∴ ∑ r = 0 m Δ r = ∑ r = 0 m 2 r - 1 ∑ r = 0 m m C r ∑ r = 0 m 1 m 2 - 1 2 m m + 1 sin 2 m 2 sin 2 m sin 2 m + 1 = m 2 - 1 2 m m + 1 m 2 - 1 2 m m + 1 sin 2 m 2 sin 2 m sin 2 m + 1 = 0 ( ∵ two rows are identical)