Trigonometry & Inverse Trigonometry Questions (1013)

If $A$, $B$, $C$ are in arithmetic progression and $B = \frac{\pi}{4}$, then $A \tan B \tan C =$
If 0 x
Ex. 11: In a triangle ABC, if \(4 \cos A \cos B + 4\sin A \sin B \sin C = 4\), then triangle ABC is
If \(x\), \(y\) and \(z\) are real numbers that satisfy the three equations \[\begin{cases} \tan(x) + \tan(y) + \tan(z) = 6 - (\cot(x) + \cot(y) + \cot(z)) \\ \tan^2(x) + \tan^2(y) + \tan^2(z) = 6 - (\cot^2(x) + \cot^2(y) + \cot^2(z)) \\ \tan^3(x) + \tan^3(y) + \tan^3(z) = 6 - (\cot^3(x) + \cot^3(y) + \cot^3(z)) \end{cases}\] Find the value of the expression \(\left(\dfrac{\tan(x)}{\tan(y)} + \dfrac{\tan(y)}{\tan(z)} + \dfrac{\tan(z)}{\tan(x)} + 3\tan(x)\tan(y)\tan(z)\right)\).
The value of $(1 + \cos \frac{2\pi}{7})(1 + \cos \frac{4\pi}{7})(1 + \cos \frac{6\pi}{7})$ is equal to
\frac{\cos 2x - 3\cos x + 1}{(\cot 2x - \cot x)\sin(x - \pi)} = 0 holds if
If \sin^{100} \theta - \cos^{100} \theta = 1, then \theta is
If for some \alpha, \beta; \alpha \le \beta, \alpha + \beta - 8 and sec (tan 2 -1 2 \alpha) + cosec (cot -1 \beta) - 36 , then \alpha + \beta is_______. 2
If \alpha, \beta, \gamma \in \left(0, \frac{\pi}{2}\right)\, then the value of \frac{\sin(\alpha + \beta + \gamma)}{\sin\alpha + \sin\beta + \sin\gamma}\ is
Given the equation \(8\cos x\left[\cos\left(\dfrac{\pi}{6}+x\right)\cdot\cos\left(\dfrac{\pi}{6}-x\right)-\dfrac{1}{2}\right]=1\), find the sum of all solutions in \([0, \pi]\) and express in the form \(k\pi\). What is \(k\)?
In the interval \(\left[-\dfrac{\pi}{2}, \dfrac{\pi}{2}\right]\) the equation \(\log_{\sin}(\cos 2\theta) = 2\) has
The equation \(\sin x - 3\sin 2x + \sin 3x = \cos x - 3\cos 2x + \cos 3x\) has solution
If $\sin x + \sin^2 x = 1$, $x \in \left(0, \dfrac{\pi}{2}\right)$, then $\left(\cos^{12} x + \tan^{12} x\right) + 3\left(\cos^{10} x + \tan^{10} x + \cos^8 x + \tan^8 x\right) + \left(\cos^6 x + \tan^6 x\right)$ is equal to
For a constant \(k\), the two roots of the quadratic equation \(3x^2 - x + k = 0\) are \(\sin\theta\) and \(\cos\theta\). The value of \(54(\sin^3\theta + \cos 3\theta)\) is:
If in a △ABC, \(\frac{a^2 - b^2}{a^2 + b^2} = \frac{\sin(A-B)}{\sin(A+B)}\), then the triangle is
Range of the function sin–1(fog(x)) is
In triangle \(ABC\) if \(\dfrac{[\Delta ABC]}{R} = 4\), then the value of \(a\cos A + b\cos B + c\cos C\) is:[Note: \(R\) is the circumradius of triangle \(ABC\) and \([\Delta ABC]\) is the area of \(\Delta ABC\)]
97. In a △ABC, AD is the bisector of the angle A meeting BC at D. If I be the incentre of the triangle then AD : DI is equal to
If in a right angled triangle the greatest side is $a$, then $\tan\left(\frac{C}{2}\right) =$
Let $f(x) = \max \{\sin x, \cos x\}$. Then the number of roots of the equation $f(x) = \frac{1}{\sqrt{2}}$ in $(0, 2\pi)$ is
\(\tan 40° + 2\tan 10°\) is equal to
A is the orthocentre of △ABC and D is reflection point of A w.r.t. perpendicular bisector of BC, then orthocentre of △DBC is:
The median $AD$ of a triangle $ABC$ is bisected at $E$ and $BE$ meets $AC$ at $F$; then $AF:AC =$
Which are correct for relation \(R\) on \(\mathbb{R}\)?
If \pi \le x \le 3\pi , then cos -1 ( 12 cos x + 5 sin x) is equal to 2 4 13 13
In a triangle, the sum of lengths of two sides is x and the product of the lengths of the same two sides is y. If x² - c² = y, where c is the length of the third side of the triangle, then the circumradius of the triangle is (JEE Main 2019)
If \alpha > \beta > \gamma > 0, then the expression cot 2 2 2 (1+\beta ) (1+\gamma ) (1+\alpha ) -1 {\beta + (\alpha-\beta) } + cot -1 {\gamma + (\beta-\gamma) }+ cot -1 {\alpha + (\gamma-\alpha) } is equal to :
The expression \(\frac{(a + b + c)(b + c - a)(c + a - b)(a + b - c)}{4b^2c^2}\) is equal to:(where symbols used have usual meanings)
\(ABC\) is a triangle. Forces \(\vec{P}\), \(\vec{Q}\), \(\vec{R}\) acting along \(IA\), \(IB\) and \(IC\) respectively are in equilibrium, where \(I\) is the incentre of \(\triangle ABC\). Then \(P : Q : R\) is
The value of $(\sin 70^\circ)(\cot 10^\circ \cot 70^\circ - 1)$ is
The angular depressions of the top and the foot of a tower, as seen from the top of a second tower which is $150$ meters high and standing on the same level as the first, are $13°$ and $\tan^{-1}\left(\frac{5}{6}\right)$ respectively. If the distance between their tops is $d$, then
If \(\tan\theta + \tan\left(\frac{\pi}{3} + \theta\right) + \tan\left(\frac{2\pi}{3} + \theta\right) = k\tan 3\theta\) then \(k\) is equal to
If $\displaystyle\sum_{r=1}^{13} \left\{\frac{1}{\sin\!\left(\tfrac{\pi}{4}+(r-1)\tfrac{\pi}{6}\right)\sin\!\left(\tfrac{\pi}{4}+r\tfrac{\pi}{6}\right)}\right\} = a\sqrt{3} + b,\ a, b \in \mathbf{Z}$, then $a^2 + b^2$ is equal to
In triangle \(ABD\), using the sine rule, if \(BD = \sqrt{p^2+q^2}\) and \(\angle ABD = \theta\), \(\angle ADB = \alpha\), then \(AB\) equals
Let M be the greatest and m be the least value of \(\sqrt{\sin^{-1} x} + \sqrt{\cos^{-1} x}\), then find the value of \((M/m)^4\).
95. In the △ABC, AB = 5 cm, AC = 12 cm and BC = 13 cm then the distance of A from the side BC is (in cm)
$PQR$ is a triangular park with $PQ = PR = 200$ m. A TV tower stands at the mid-point of $QR$. If the angles of elevation of the top of the tower from $P$, $Q$ and $R$ are $45°$, $30°$ and $30°$ respectively, then the height of the tower (in meters) is
175. If \(A\) lies in the fourth quadrant and \(3\tan A + 4 = 0\), then \(5\sin 2A + 2\sin A + 4\cos A\) is equal to:
810. In \(\triangle ABC\) if inradius \(r = 1\), circumradius \(R = 3\) and semiperimeter \(s = 7\), then find the value of \((a^2 + b^2 + c^2)\), where \(a, b, c\) are the sides of triangle \(ABC\).
Let $S = \{\theta \in [0, 2\pi): \tan(\pi\cos\theta) + \tan(\pi\sin\theta) = 0\}$. Then $\displaystyle\sum_{\theta \in S} \sin^2\left(\theta + \frac{\pi}{4}\right)$ is equal to
If $\tan 15° + \frac{1}{\tan 75°} + \frac{1}{\tan 105°} + \tan 195° = 2a$, then the value of $\left(a + \frac{1}{a}\right)$ is:
158. If \((\sin^{-1} x)^2 + (\sin^{-1} y)^2 + 2\sin^{-1} x \sin^{-1} y = \pi^2\), then \(x^2 + y^2\) is equal to:
If |k| = 5 and 0°
The equation sin x + sin y + sin z = -3 for 0
Ex. 24: Statement I In a triangle ABC, \(\cos^2\dfrac{A}{2}\) has the value equal to \(\dfrac{s(s-a)}{abc}\)Statement II In a triangle ABC, \(\cos\dfrac{A}{2} = \sqrt{\dfrac{(s-b)(s-c)}{bc}}\), \(\cos\dfrac{B}{2} = \sqrt{\dfrac{(s-a)(s-c)}{ac}}\), \(\cos\dfrac{C}{2} = \sqrt{\dfrac{(s-a)(s-b)}{ab}}\)
101. Two straight roads intersect at 30°. From the junction, two persons A and B start walking at the same time, one on each road. A walks at the rate of 5 km/h. At the end of 3 hours they are 9 km apart. If B walks at uniform rate then the speed of B is
Ex. 45. If $a$, $P$, $y$ are acute angles and $\cos \theta = \frac{\sin P}{\sin a}$, $\cos \theta = \frac{\sin y}{\sin a}$ and $\cos(\theta - \phi) = \sin P \sin y$, then the value of $\tan^2 a - \tan^2 P - \tan^2 y$ is equal to
171. The least positive value of \(x\) satisfying the equation \(\dfrac{\sin x}{\cos 3x} + \dfrac{\sin 3x}{\cos 9x} + \dfrac{\sin 9x}{\cos 27x} = 0\) is:
152. 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:
276. If \(\dfrac{1}{2}\sin^{-1}\!\left(\dfrac{3\sin 2\alpha}{5+4\cos 2\alpha}\right) = \tan^{-1} x\), then the possible value of \(x\) is: