If 1 + tanα1 + tan4α = 2, α ∈ 0, π16,then α = ?
π20
π30
π40
π50
If cosθ = cosα - cosβ1 - cosαcosβ, then one of the values of tanθ2 is
cotβ2tanα2
tanα2tanβ2
tanβ2cotα2
tan2α2tan2β2
The value of the expression 1 + sin2αcos2α - 2πtanα - 3π4 - 14sin2αcotα2 + cot3π2 + α2 is
0
1
sin2α2
sin2α
If 16sinθ, cosθ and tanθ are in geometric progression, then the solution set of θ is
2nπ ± π6
2nπ ± π3
nπ + - 1nπ3
nπ + π3
In ∆ABC if x = tanB - C2tanA2, y = tanC - A2tanB2 and z = tanA - B2tanC2, then x + y + z = ?
xyz
- xyz
2xyz
12xyz
B.
Given, x = tanB - C2tanA2 y = tanC - A2tanB2 and z = tanA - B2tanC2⇒ x = b - cb + c ∵tanB - C2 = b - cb + ccotA2Y = c - ac + a and z = a - ba + bNow, 1 + x1 - x = b + c + b - cb + c - b + c By componendo and dividendo⇒ 1 + x1 - x = bcSimilarly,1 + y1 - y = ca and 1 + z1 - z = ab∴ 1 + x1 - x1 + y1 - y1 + z1 - z = bc × ca × ab = 1⇒ 1 + x1 + y1 + z = 1 - x1 - y1 - z⇒ 1 + x + y + z + xy + yz + zx + xyz = 1 - x + y + z + xy + yz + zx - xyz⇒ x + y + z = - xyz
If A > 0, B > 0 and A + B = π3, then the maximum value of AtanB is
13
12
3
In ∆ABC, if bcosθ = c - a, (where θ is an acute angle), then (c - a) tanθ = ?
2cacosB2
2acsinB2
2casinB2
If tanα and tanβ are the roots of the equation x2 + px + q = 0, then the value ofsin2α + β + pcosα + βsinα + β + qcos2α + β
p + q
p
q
pp + q
1 + cos10° + cos20° + cos30° = ?
4sin10°sin20°sin30°
4cos5°cos10°cos15°
4cos10°cos20°cos30°
4sin5°sin10°sin15°
The value of 1 + sin2π9 + icos2π91 + sin2π9 - icos2π93 is :
- 123 - i
123 - i
121 - i3
- 121 - i3