If sin(A) + sin(B) + sin(C) = 0 and cos(A) + cos(B) + cos(C) = 0, then cos (A + B) + cos (B + C) + cos(C + A) is equal to
cos(A + B + C)
2
1
0
If tanθ . tan120° - θtan120° + θ = 13, then θ is equal to
nπ3 + π18, n ∈ Z
nπ3 + nπ12, n ∈ Z
nπ12 + π12, n ∈ Z
nπ3 + π6, n ∈ Z
1 + cosπ8 - isinπ81 + cosπ8 + isinπ88 = ?
- 1
12
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
sin2α2
sin2α
D.
We have,1 + sin2αcos2α - 2πtanα - 3π4 - 14sin2αcotα2 + cot3π2 + α2⇒ cosα + sinα2cos2αtanα - tan3π41 + tanαtan3π4 - 142sinαcosαcotα2 - tanα2= cosα + sinα2cos2α - sin2αtanα + 11 - tanα - 14 . 2sinαcosαcosα2sinα2 - sinα2cosα2= 1 - sinαcos2α2sinα2cosα2 = 1 - sinαcos2αsinα= 1 - cos2α = 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
If A > 0, B > 0 and A + B = π3, then the maximum value of AtanB is
13
3
In ∆ABC, if bcosθ = c - a, (where θ is an acute angle), then (c - a) tanθ = ?
2cacosB2
2acsinB2
2casinB2