The value of
tanα + 2tan2α + 4tan4α + ... + 2n - 1tan2n - 1α + 2ncot2nα is
cot2nα
2ntan2nα
0
cotα
If tanαπ4 = cotβπ4, then
α + β = 0
α + β = 2n
α + β = 2n + 1
α + β = 2(2n + 1), ∀ n is an integer
The principal value of sin-1tan- 5π4 is
π4
- π4
π2
- π2
The value of cosπ15cos2π15cos4π15cos8π15
116
- 116
1
B.
cosπ15cos2π15cos4π15cos8π15= 142cos4π15cosπ152cos8π15cos2π15= 14cos60° + cos36°cos120° + cos72°= 1412 + 5 + 14- 12 + 5 - 14 ∵ cos36° = 5 + 14 and cos72° = 5 - 14= 14- 14 + 125 - 14 - 5 + 14 + 5 - 116= 1412- 12 = - 116
The principal amplitude of sin40° + icos40°5
70°
- 110°
110°
- 70°
Find the general solution of secθ + 1 = 2 + 3tanθ
The real part of 1 - cosθ + 2isinθ- 1
13 + 5cosθ
15 - 3cosθ
13 - 5cosθ
15 + 3cosθ
The value of sin36°sin72°sin108°sin144° is equal to
14
34
516
If sinA = 110 and sinB = 15 where A and B are positive acute angles, then A + B is equal to
π
π3
The expression tan2α + cot2α is
≥ 2
≤ 2
≥ - 2
None of these