Trigonometry & Inverse Trigonometry Questions (1013)

Let \(P = \{\theta : \sin\theta - \cos\theta = \sqrt{2}\cos\theta\}\) and \(Q = \{\theta : \sin\theta - \cos\theta = \sqrt{2}\sin\theta\}\) be two sets. Then,
The value of \(\cos A + \cos B + \cos C\) is
241. If \(\dfrac{\cos x + \cos y + \cos z}{\cos(x+y+z)} = 2\) and \(\dfrac{\sin x + \sin y + \sin z}{\sin(x+y+z)} = 2\), then the value of \(\cos(x+y) + \cos(y+z) + \cos(z+x)\) is equal to: (where \(x,\, y,\, z \in R\))
The value of \(2ca\sin\!\left(\dfrac{A-B+C}{2}\right)\) equals
Find the value of \(\cos\dfrac{\pi}{2^2} \cdot \cos\dfrac{\pi}{2^3} \cdots \cos\dfrac{\pi}{2^{10}} \cdot \sin\dfrac{\pi}{2^{10}}\).
If \(\alpha\), \(\beta\) are two values of \(\theta\) obtained from the equation \(a\cos\theta + b\sin\theta = c\) then the value of \(\tan\frac{\alpha+\beta}{2}\) is
If \(2\sin\theta + 1 = 0\) and \(\sqrt{3}\tan\theta = 1\) then the most general value of \(\theta\) is
Let a = sin α, b = cos α and c = √(1 + sin α cos α). In a triangle with sides a, b, c, what is the angle C?
94. The diameter of the circumcircle of a triangle with sides 5, 6 and 7 is
If \(\frac{1+\sin 2x}{1-\sin 2x} = \tan^2(a+x)\) for all \(x\) then the numerically smallest value of \(a\) is
Calculate m = \sum_{k=1}^{17} \cos\left(\frac{k\pi}{9}\right) = \cos\left(\frac{\pi}{9}\right) + \cos\left(\frac{2\pi}{9}\right) + \cos\left(\frac{3\pi}{9}\right) + \ldots + \cos\left(\frac{17\pi}{9}\right), and find the value of (m^2 + m + 2).
The value of the expression \cos^2\left(\frac{\pi}{8}\right) + \cos^2\left(\frac{3\pi}{8}\right) + \cos^2\left(\frac{5\pi}{8}\right) + \cos^2\left(\frac{7\pi}{8}\right) is
If $\sin^{-1}\frac{1}{4} + \sin^{-1}\frac{3}{5} = \sin^{-1}x$, then the value of $x$ is
The value of \(\frac{\cos A}{a} + \frac{\cos B}{b} + \frac{\cos C}{c}\) is
The minimum value of the expression \(\dfrac{\sin^3\alpha + 6\sin^2\alpha + \sin\alpha + 2\cos^2\alpha - 8}{\sin\alpha - 1}\) is equal to:
If A + B = \frac{\pi}{3}, A, B > 0, then the maximum value of \tan A \cdot \tan B is
The value of \(r_1 + r_2 + r_3 - 4R\) is
The value of \(\dfrac{1 - \tan^2 15°}{1 + \tan^2 15°}\) is
The value of \frac{2\cos^3\left(\frac{\pi}{2}+x\right)\cot(3\pi+x)\sec(x-3\pi)\operatorname{cosec}\left(\frac{3\pi}{2}-x\right)}{\cot x\tan^2(x-\pi)\sin(x-2\pi)}\) is equal to
Given that \(\sin x - \sin 2x + \sin 3x = 0\)Find the number of values of \(x\) that are possible.
In △ABC, If A − B = 120° and R = 8r, then the value of \(\frac{1 + \cos C}{1 - \cos C}\) equals:(All symbols used have their usual meaning in a triangle)
In an isosceles triangle ABC, AB = AC. If the vertical angle ∠A is 20°, then a³ + b³ is equal to
If \(\alpha = \dfrac{\pi}{3}\), find the value of \(\dfrac{\cos 2\alpha + \sec\alpha + 3\sqrt{3}}{\tan\alpha}\).
The number of all possible 5-tuples (a_1, a_2, a_3, a_4, a_5) such that a_1 + a_2 \sin x + a_3 \cos x + a_4 \sin 2x + a_5 \cos 2x = 0 holds for all x is
Which are correct?(A) \(\cot^{-1}x=\tan^{-1}(1/x)\ \forall x\in\mathbb{R}\setminus\{0\}\)(B) \(f(x)=\text{sgn}(e^x)\) is into(C) \(f:\mathbb{R}^+\to\mathbb{R},\,f(x)=\sin x+x\) is odd(D) \(f(x)=e^x/e^{[x]}\) is periodic
If \(\sum_{m=1}^{6} \csc\left(\alpha + (m-1)\frac{\pi}{4}\right)\csc\left(\alpha + \frac{m\pi}{4}\right) = 4\sqrt{2}\), where \(\alpha \in (0, \pi)\) then \(\alpha\) can be:
If A, B, C, D are the angles of a quadrilateral, then \(\frac{\sum \tan A}{\sum \cot A}\) is equal to
If \(\cos\frac{p}{q} + \cos\frac{q}{q} = 0\), then the different values of \(q\) are in AP, whose common difference is
176. If \(\alpha = \sin\theta\,|\sin\theta|\) and \(\beta = \cos\theta\,|\cos\theta|\) where \(\theta \in \left[\dfrac{199\pi}{2},\, 100\pi\right]\), then:
Question nos. 687 to 689Column-1 represents a condition to form trigonometric equation. Column-2 represents the value of \(\sin\theta + \cos\theta\) and Column-3 represents the general value of \(\theta\) satisfying the trigonometric equation.Column-1Column-2Column-3(I) If \(2^{\sin\theta}\), \(\sqrt{2}\) and \(2^{\cos\theta}\) are three terms of a decreasing G.P.(i) \(\dfrac{\sqrt{3}+1}{2}\)(P) \(\theta = 2n\pi - \dfrac{\pi}{2}\)(II) If \(\cos\theta\), \(\sec\theta\) and \(\cot\theta\) are three positive numbers in H.P.(ii) \(\sqrt{2}\)(Q) \(\theta = 2n\pi + \dfrac{\pi}{6}\)(III) If \(2\log\sec\theta\), \(\log 2\) and \(2\log\text{cosec}\,\theta\) are in A.P.(iii) \(-1\)(R) \(\theta = 2n\pi + \dfrac{\pi}{2}\)(IV) If G.M. of \((2+\sin\theta)\), \((3+\sin\theta)\) and \((4+\sin\theta)\) is equal to cube root of 6.(iv) \(1\)(S) \(\theta = 2n\pi + \dfrac{\pi}{4}\)688. Which of the following options is the only correct combination?
The maximum value of a \sin 2x + b \cos 2x for all real x is
If \(0 \leq \theta \leq 2\pi\) and \(2\sin^2 \theta - 5\sin \theta + 2 > 0\), then find the range of \(\theta\).
If \(\sum_{m=1}^{6} \csc\left(\alpha + (m-1)\dfrac{\pi}{4}\right)\csc\left(\alpha + \dfrac{m\pi}{4}\right) = 4\sqrt{2}\), where \(\alpha \in (0, \pi)\) then \(\alpha\) can be:
If \(x + \sin y = 2014\) and \(x + 2014\cos y = 2013\), where \(0 \le y \le \frac{\pi}{2}\), then find the value of \([x+y] - 2005\) (where \([\cdot]\) denotes greatest integer function).
If \(1 - \frac{\cos^2 A}{a^2} - 1 - \frac{\cos^2 B}{b^2} = \frac{2}{r_2} - \frac{2}{r_3}\), then the triangle is
The number of solutions of the equation \(|\cot x| = \cot x + \frac{1}{\sin x}\), \(0
If |sin x + cos x| = |sin x| + |cos x|, x ∈ [0, 2π] then the solution set is
Let \(\theta = \sin^{-1}\left(\dfrac{3\sin 2\alpha}{5 + 4\cos 2\alpha}\right)\). Then \(\tan^{-1} x = \dfrac{\theta}{2}\) where \(x\) equals:
If \cos^{-1}\left(\frac{1-x^2}{1+x^2}\right) , then
We have tan(15°) + tan(30°) = –p and tan(15°) + tan(30°) = –p. Given that tan(45°) = 1, find the value of (2 + q – p) where q – p = 1.
Find the value of \(\cos\left(\frac{2\pi}{7}\right)\cos\left(\frac{4\pi}{7}\right)\cos\left(\frac{8\pi}{7}\right)\)
Given \(f_k(x) = \dfrac{1}{k}(\sin^k x + \cos^k x)\), find the value of \(f_4(x) - f_6(x)\).
A vertical tower subtends an angle of $60°$ at a point on the same level as the foot of the tower. On moving $100$ m further from the first point in line with the tower, it subtends an angle of $30°$ at the point. If the height of the tower is $H$ m, then the value of $\frac{H}{\sqrt{3}}$ (in meters) is
If \(\frac{\cos(\alpha+\gamma)}{\cos(\alpha-\gamma)} = \cos 2\beta\) then \(\tan\alpha\), \(\tan\beta\) and \(\tan\gamma\) are in
The value of \(\sin\left(\frac{\pi}{14}\right)\sin\left(\frac{3\pi}{14}\right)\sin\left(\frac{5\pi}{14}\right)\) is
The number of solutions of the equation \(e^{\sin x} - e^{-\sin x} = 4\) is
Let a, b, c be three non-zero real numbers such that the equation acosx + 2bsinx = c, x ∈ [−π/2, π/2], has two distinct real roots α and β with α + β = π/3. Then, the value of b/a is __________________________.
Let $\alpha$ and $\beta$ respectively be the maximum and minimum values of the function $f(\theta)=4\left(\sin^4\!\left(\dfrac{7\pi}{2}-\theta\right)+\sin^4(11\pi+\theta)\right)-2\left(\sin^6\!\left(\dfrac{3\pi}{2}-\theta\right)+\sin^6(9\pi-\theta)\right)$, $\theta\in\mathbb{R}$. Then $\alpha+2\beta$ is equal to:
For \(x \in (0, \pi)\), the equation \(\sin x + 2 \sin 2x - \sin 3x = \frac{3}{5}\) has
If PQ be a vertical tower subtending angles α, β and γ at the points A, B and C respectively on the line in the horizontal plane through the foot D of tower and on the same side of it, then BC cot α - CA cot β + AB cot γ is equal to