If sinθ and cosθ are the roots of the equation ax2 - bx + c = 0, then a, b and c satisfy the relation
a2 + b2 + 2ac = 0
a2 - b2 + 2ac = 0
a2 + c2 + 2ab = 0
a2 - b2 - 2ac = 0
If sinθ + cosθ = 0 and 0 < θ < π, then θ
0
π4
π2
3π4
The value of cos15° - sin15° is
12
- 12
122
The period of the function f(x) = cos4x + tan3x is
π
π3
If x + 1x = 2cosθ, then for any integer n, xn + 1xn is equal to
2cosnθ
2sinnθ
2icosnθ
2isinnθ
Prove that the equation cos(2x) + asin(x) = 2a - 7 possesses a solution if 2 ≤ a ≤ 6.
Find the values of x. - π < x < π, x ≠ 0 satisfying the equation,
g1 + cosx + cos2x + ... ∞ = 43
The value of cotx - tanxcot2x is
1
2
- 1
4
The number of points of intersection of 2y = 1 and y = sin(x), in - 2π ≤ x ≤ 2π is
3
If cosA3 = cosB4 = 15, - π2 < A < 0, - π2 < B < 0 then value of 2sinA + 4sinB is
- 2
- 4
C.
cosA3 = 15⇒ cosA = 35 ⇒ sinA = - 45 ∵ sinA = 1 - cos2Aand cosB = 45 ⇒ sinA = - 35Therefore, 2sinA + 4sinB= 2- 45 + 4- 35 = - 205 = - 4