Trigonometry & Inverse Trigonometry Questions (1013)

Given that \(\cos(\alpha + \beta) = \dfrac{4}{5}\) and \(\sin(\alpha - \beta) = \dfrac{5}{13}\), where \(\alpha + \beta \in \left[0, \dfrac{\pi}{2}\right]\) and \(\alpha - \beta \in \left[0, \dfrac{\pi}{4}\right]\), then \(\tan 2\alpha\) is equal to:
The sum of solutions in \((0, 2\pi)\) of the equation \(\cos x \cos\!\left(\dfrac{\pi}{3} - x\right)\cos\!\left(\dfrac{\pi}{3} + x\right) = \dfrac{1}{4}\) is:
If \(\cos 2\theta = \sin\alpha\) then the most general relation between \(\theta\) and \(\alpha\) is (where \(n \in \mathbb{Z}\))
A tower \(T_1\) of height 60 m is located exactly opposite to a tower \(T_2\) of height 80 m on a straight road. From the top of \(T_1\), if the angle of depression of the foot of \(T_2\) is twice the angle of elevation of the top of \(T_2\), then the width (in m) of the road between the feet of the towers \(T_1\) and \(T_2\) is
Paragraph (Questions 7-8): Let the incircle of \(\triangle ABC\) touch sides \(BC, CA, AB\) at \(A_1, B_1, C_1\) respectively. The incircle of \(\triangle A_1B_1C_1\) touches its sides \(B_1C_1, C_1A_1, A_1B_1\) at \(A_2, B_2, C_2\) respectively and so on.Find \(\lim_{n \to \infty} \angle A_n\)
If \(\cos^2 x = t\), and the equation \(5\left[\frac{1-t}{t} - t\right] = 2(2t-1) + 9\) is satisfied, then find the value of \(\cos 4x\).
With the usual notation, in triangle ABC, if $\angle A + \angle B = 120°$, $a = \sqrt{3} + 1$ and $b = \sqrt{3} - 1$, then the ratio $\angle A : \angle B$ is
If in the pedal triangle DEF of an acute-angled triangle ABC, the sides are denoted by l, m, n, then l/(a²) + m/(b²) + n/(c²) is equal to
If \(\tan\theta_1, \tan\theta_2, \tan\theta_3\) are the real roots of the equation \(x^3 - (a+1)x^2 + (b-a)x - b = 0\), where \(\theta_1 + \theta_2 + \theta_3 \in (0, \pi)\), then \(\theta_1 + \theta_2 + \theta_3\) is equal to
AB is a vertical pole with B at the ground level and A at the top. A man finds that the angle of elevation of point A from a certain point C on the ground is 60°. He moves away from the pole along the line BC to a point D such that CD = 7 m. From D the angle of elevation of the point A is 45°. Then the height of the pole is
\(3 \csc 20° - \sec 20°\) is equal to
The value of \(\sqrt{3}\csc 20° - \sec 20°\) is equal to
The number of values of \(x\) in \([0, 5\pi]\) satisfying the equation \(3\sin^2 x - 7\sin x + 2 = 0\) is
Solution set of the inequality \((\cot^{-1}x)^2 - 5(\cot^{-1}x) + 6 > 0\) is
In triangle ABC, given a/sin A = 2√2/sin 30° = 4/sin C. Find angles C and A.
Two flagstaffs stand on a horizontal plane. A and B are two points on the line joining their feet and between them. The angles of elevation of the tops of the flagstaffs as seen from A are 30° and 60° and as seen from B are 60° and 45°. If AB is 30 m, the distance between the flagstaffs in metres is
If sin θ + cos θ = a and sin³ θ + cos³ θ = b, then the value of λ³ + μ³ + ν³ is, where λa + μb + νa = 0 and λ, μ, ν are independent of θ.
The value of expression \(\frac{8}{1 + \tan(100°)}\) is equal to
If $\dfrac{\cos^248°-\sin^212°}{\sin^224°-\sin^26°}=\dfrac{\alpha+\beta\sqrt{5}}{2}$, where $\alpha,\beta\in\mathbb{N}$, then $\alpha+\beta$ is equal to _____.
If $a\sin\theta - b\cos\theta = -\sin 4\theta$ and $a\cos\theta + b\sin\theta = \frac{5}{2} - \frac{3}{2}\cos 4\theta$, then $(a+b)^{2/5} + (a-b)^{2/5}$ is _______.
If $\tan\left(142\frac{1}{2}°\right) = 2 + \sqrt{2} - \sqrt{\mu} - \sqrt{\lambda}$, then $\mu + \lambda =$
The general solution of sin 2θ sec θ + √3 tan θ = 0.
Two parallel chords are drawn on the same side of the centre of a circle of radius R. It is found that they subtend an angle of θ and 2θ at the centre of the circle. The perpendicular distance between the chords is
Which of the following is the least?(a) \(\sin 3\)(b) \(\sin 2\)(c) \(\sin 1\)(d) \(\sin 7\)
In a triangle ABC, if \(\tan\frac{A}{2}\tan\frac{C}{2} = \frac{1}{3}\) and \(ac = 4\), then the least value of b is:(notation have their usual meaning)
Statement I: \(\tan 50° - \tan 30° - \tan 20° = \tan 50° \tan 30° \tan 20°\)Statement II: If \(x = y + z\), then \(\tan x - \tan y - \tan z = \tan x \tan y \tan z\)
In a triangle ABC, if \(\tan A = 2 \sin 2C\) and \(3 \cos A = 2 \sin B \sin C\) then possible values of C is/are:
The minimum value of the function f(x) = sin x/√(1 - cos² x) + cos x/√(1 - sin² x) + tan x/√(sec² x - 1) + cot x/√(cosec² x - 1) whenever it is defined is
Angles A, B and C of a △ABC are in AP. If \(\frac{b}{c} = \frac{\sqrt{3}}{2}\), then ∠A is equal to
The complete set of values of x satisfying the inequality sin-1(sin 5) > x2 - 4x is ( 2 - √(1 - 2π), 2 + √(1 - 2π) ), then l =
If \(\sec A \tan B + \tan A \sec B = 91\), then the value of \((\sec A \sec B + \tan A \tan B)^2\) is equal to:
Let ABC be a right triangle with $\angle BAC = \frac{\pi}{2}$, then $\left(\frac{r_2}{2R^2} + \frac{r}{R}\right)$ is equal to: (where symbols used have usual meaning in a triangle)
In triangle ABC, if \(2a^2b^2 + 2b^2c^2 = a^4 + b^4 + c^4\), then angle B is equal to
All positions of point P for which triangle DEF is isosceles lie on
If \(x + \frac{1}{x} = 2\), the principal value of \(\sin^{-1}x\) is
If \(\dfrac{1}{16}(\cos 36^\circ \sin 54^\circ)^2 - \left(\dfrac{1}{4}\sin 36^\circ \sin 36^\circ\right)^2 \equiv \dfrac{\sqrt{a}-b}{c}\), find \((a + b + c)\).
In a right angled triangle ABC, the bisector of the right angle C divides AB into segments x and y. If \(\tan\frac{A-B}{2} = t\), then x : y is equal to
If in a $\triangle ABC$, $\sum\sin 3A = 0$, then at least one angle of $\triangle ABC$ is:
The number of values of \(x\) in the interval \([0, 3\pi]\) satisfying the equation \(2\sin^2 x + 5\sin x - 3 = 0\) is
The number of pairs $(x, y)$ satisfying the equations $\sin x + \sin y = \sin(x + y)$ and $|x| + |y| = 1$ is:
Consider f, g and h be three real valued functions defined on ℝ.Let f(x) = sin 3x + cos x, g(x) = cos 3x + sin x and h(x) = f²(x) + g²(x)Number of point(s) where the graphs of the two functions, y = f(x) and y = g(x) intersects in [0, π], is:
Find the number of solutions of the equations \(2\sin^2 x + \sin^2 2x = 2\) and \(\sin 2x + \cos 2x = \tan x\) in \([0, 4\pi]\) satisfying the condition \(2\cos 2x + \sin x \le 2\).
If triangle DEF is equilateral, then P
The value of x in \left(0, \frac{π}{2}\right) satisfying the equation \frac{\sqrt{5}-1}{4} \cdot \frac{1}{\sin x} + \frac{\sqrt{10+2\sqrt{5}}}{4} \cdot \frac{1}{\cos x} = 2 is
If $\sin x + \cos x + \tan x + \cot y = 4$, where $x, y \in [0, \frac{\pi}{2}]$, then $\tan(\frac{y}{2})$ is a root of the equation:
In triangle ABC, the ratio \(\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}\) is always equal to (All symbols used have usual meaning in a triangle.)
If \sin^{-1}: [-1,1] \to \left[-\frac{\pi}{2}, \frac{\pi}{2}\right] and \cos^{-1}: [-1,1] \to [0, \pi] be two bijective functions, respectively inverses of bijective functions \sin: \left[-\frac{\pi}{2}, \frac{\pi}{2}\right] \to [-1,1] and \cos: [0,\pi] \to [-1,1], then \sin^{-1}x + \cos^{-1}x is
703. Let \(f(x) = \cos^{-1}\!\left(\sqrt{\sin^{-1}\!\left(\sec\!\left(\ln\!\left(\dfrac{2x^2+3x-2}{x^2-3x+2}\right)\right)\right)}\right)\). Find the value of \(1 + \left(\displaystyle\sum \alpha_i^2\right)\) where \(\alpha_i\) represents the integers in the range of \(f(x)\). If there are no integers in the range of \(f(x)\), then enter your answer as zero.
If the sum of all values of \(\theta\), \(0 \le \theta \le 2\pi\) satisfying the equation\((8\cos^4 \theta - 3)(\cot \theta + \tan \theta - 2)(\cot \theta + \tan \theta + 2) = 12\)is \(k\pi\), then \(k\) is equal to:
Given the equations with solutions in the interval (0, π/2):(i) sin a = 1/2, so cos a = √3/2(ii) cos β = 1/3, so sin β = √(8/9)(iii) sin γ = cos γ = 1/√2(iv) cos γ = 1, sin γ = 0Find: cos a + cos β + cos γ