Skip to main content
Back to TRIGONOMETRIC EQUATIONS

Your Progress

0 / 294 Answered
0
Correct
0
Incorrect
0%
Accuracy
JEE • MATHEMATICS • TRIGONOMETRIC EQUATIONS

Trigonometric equations practice · Medium

Try a question, then open “View answer” to check it. Sign in to submit answers and save progress.

Practice format and chapter quiz

These sets use single-correct-answer MCQs. They do not cover every JEE Main or JEE Advanced question format and are not full-length mock papers.

Take a chapter quiz →
Showing 31-60 of 294 questions
31 Medium
31 of 294
Analyzing +4 | -1
The number of solutions of sin⁡3x=cos⁡2x\sin 3 x=\cos 2 x, in the interval (π2,π)\left(\frac{\pi}{2}, \pi\right) is
View answer and explanation
Correct option: D
1
Option D (1) is correct because after simplifying the equation sin⁡3x=cos⁡2x\sin 3x = \cos 2x and considering the interval (π2,π)(\frac{\pi}{2}, \pi), there is only one solution.
32 Medium
32 of 294
Analyzing +4 | -1
If xx and yy are acute angles such that cos⁡x+cos⁡y=32\cos x+\cos y=\frac{3}{2} and sin⁡x+sin⁡y=34\sin x+\sin y=\frac{3}{4}, then sin⁡(x+y)\sin (x+y) equals
View answer and explanation
Correct option: D
45\frac{4}{5}
Option D (45\frac{4}{5}) is correct because it is the value of sin⁡(x+y)\sin(x+y) calculated using the given equations and trigonometric identities.
33 Medium
33 of 294
Analyzing +4 | -1
If asin⁡x+bcos⁡(x+θ)+bcos⁡(x−θ)=da \sin x+b \cos (x+\theta)+b \cos (x-\theta)=d, then the minimum value of ∣cos⁡θ∣|\cos \theta| is
View answer and explanation
Correct option: A
12∣b∣d2−a2\frac{1}{2|b|} \sqrt{d^2-a^2}
Option A (12∣b∣d2−a2\frac{1}{2|b|} \sqrt{d^2-a^2}) is correct because it represents the minimum value of |cos θ| derived from the given equation.
34 Medium
34 of 294
Understanding +4 | -1
Solution of the inequality sin⁡x>1/2\sin x > 1 / \sqrt{2} belongs to
View answer and explanation
Correct option: A
(2nπ+π4,2nπ+3π4)\left(2 n \pi+\frac{\pi}{4}, 2 n \pi+\frac{3 \pi}{4}\right) where n∈Zn \in \mathbb{Z}
Option A ((2nπ+π4,2nπ+3π4)\left(2 n \pi+\frac{\pi}{4}, 2 n \pi+\frac{3 \pi}{4}\right) where n∈Zn \in \mathbb{{Z}}) is correct because sin⁡x>1/2\sin x > 1/\sqrt{{2}} when xx is between π/4\pi/4 and 3π/43\pi/4 in each period.
35 Medium
35 of 294
Analyzing +4 | -1
The number of solutions of 2sin⁡x+cos⁡x=32 \sin x+\cos x=3 is
View answer and explanation
Correct option: D
No solution
Option D (No solution) is correct because the maximum value of 2sin⁡x+cos⁡x2 \sin x + \cos x is 5\sqrt{5}, which is less than 3.
36 Medium
36 of 294
Analyzing +4 | -1
The total number of ordered pairs (r,  θ)\left( {r,\,\,\theta } \right) satisfying r  sin⁡  θ=3,  r=4(1+sin⁡  θ)r\,\,\sin \,\,\theta = 3,\,\,r = 4\left( {1 + \sin \,\,\theta } \right), where r>0r > 0 and θ∈[−π,  π]\theta \in \left[ { - \pi ,\,\,\pi } \right] is
View answer and explanation
Correct option: B
2\mathrm{2}
Option B (2) is correct because solving the system of equations yields two valid solutions for θ\theta within the given interval.
37 Medium
37 of 294
Analyzing +4 | -1
The number of roots of the equation ∑k=17sin⁡(kx)=7sin⁡4x\sum\limits_{{k=1}}^7 \sin (k x)=7 \sin 4 x in the interval [0,2π][0,2 \pi] is
View answer and explanation
Correct option: D
9
The correct answer is D (9) because the equation simplifies to sin(4x) = 0 or cos(x) = 1, leading to 9 solutions in the interval [0, 2π].
38 Medium
38 of 294
Analyzing +4 | -1
If x1x_1 and x2x_2 are two positive values of xx for which 2cos⁡x,∣cos⁡x∣2 \cos x,|\cos x| and 3sin⁡2x−23 \sin ^2 x-2 are in GP. The minimum value of ∣x1−x2∣\left|x_1-x_2\right| is
View answer and explanation
Correct option: C
2cos⁡−1(23)2 \cos ^{-1}\left(\frac{2}{3}\right)
Option C (2cos⁡−1(23)2 \cos ^{-1}\left(\frac{2}{3}\right)) is correct because it represents the minimum difference between two positive values of x that satisfy the given geometric progression condition.
39 Medium
39 of 294
Application +4 | -1
The general solution of the equation tan⁡θ+tan⁡2θ+3tan⁡θtan⁡2θ=3\tan \theta+\tan 2 \theta+\sqrt{3} \tan \theta \tan 2 \theta=\sqrt{3} is
View answer and explanation
Correct option: A
θ=(3n+1)π9\theta=(3 n+1) \frac{\pi}{9}
Option A (θ=(3n+1)π9\theta=(3 n+1) \frac{{\pi}}{{9}}) is correct because it represents the general solution derived from solving the given trigonometric equation.
40 Medium
40 of 294
Application +4 | -1
If 3sin⁡α=5sin⁡β3 \sin \alpha=5 \sin \beta, then tan⁡α+β2tan⁡α−β2\frac{\tan \frac{\alpha+\beta}{2}}{\tan \frac{\alpha-\beta}{2}} is equal to
View answer and explanation
Correct option: D
4
Option D (4) is correct because by applying the componendo and dividendo rule and the sum-to-product trigonometric identities, the expression simplifies to 4.
41 Medium
41 of 294
Application +4 | -1
The most general solution of the equation
8  tan⁡2  θ2=1+sec⁡  θ,    is8\,\,{\tan ^2}\,\,\frac{\theta }{2} = 1 + \sec \,\,\theta ,\;\,\,\mathrm{is}
View answer and explanation
Correct option: A
θ=2n  π  ±  cos⁡−1  (13)\theta = 2n\;\pi \,\, \pm \,\,{\cos ^{ - 1}}\,\,\left( {\frac{1}{3}} \right)
Option A (θ=2n  π ± cos⁡−1 (13)\theta = 2n\;\pi \, \pm \,{\cos ^{ - 1}}\,\left( {\frac{1}{3}} \right)) is correct because it represents the general solution obtained by solving the given trigonometric equation.
42 Medium
42 of 294
Application +4 | -1
The equation kcos⁡x−3sin⁡x=k+1k \cos x-3 \sin x=k+1 is solvable only if
View answer and explanation
Correct option: B
k∈(−∞,4]k \in(-\infty, 4]
Option B (k∈(−∞,4]k \in(-\infty, 4]) is correct because the equation is solvable only when the absolute value of (k+1) is less than or equal to the square root of (k2 + 9), leading to k <= 4.
43 Medium
43 of 294
Analyzing +4 | -1
If sum of all the solutions of the equation 8cos⁡x(cos⁡(π6+x)cos⁡(π6−x)−12)=18 \cos x\left(\cos \left(\frac{\pi}{6}+x\right) \cos \left(\frac{\pi}{6}-x\right)-\frac{1}{2}\right)=1 in [0,π][0, \pi] is kπ{k} \pi, then k{k} is equal to:
View answer and explanation
Correct option: C
139\frac{13}{9}
The value of k is 13/9. This is found by simplifying the trigonometric equation, solving for x, and summing the solutions in the given interval.
44 Medium
44 of 294
Analyzing +4 | -1
If cos⁡A=mcos⁡B\cos A=m \cos B and cot⁡(A+B2)=λ/tan⁡(B−A2)\cot \left(\frac{A+B}{2}\right)=\lambda/\tan \left(\frac{B-A}{2}\right), then λ\lambda is equal to
View answer and explanation
Correct option: C
m+1m−1\frac{m+1}{m-1}
Option C (m+1m−1\frac{{m+1}}{{m-1}}) is correct because it's derived by applying the componendo and dividendo rule and trigonometric identities to the given equation.
45 Medium
45 of 294
Understanding +4 | -1
If sin⁡θ=12\sin \theta=\frac{1}{2} and tan⁡θ=13,∀ n∈I\tan \theta=\frac{1}{\sqrt{3}}, \forall \, n \in I, then most general value of θ\theta is
View answer and explanation
Correct option: A
2nπ+π6,∀ n∈I2 n \pi+\frac{\pi}{6}, \forall \, n \in I
The correct answer is 2nπ+π6,∀,n∈I2 n \pi+\frac{{\pi}}{{6}}, \forall \\, n \in I because it represents the general solution that satisfies both sin⁡θ=12\sin \theta = \frac{{1}}{{2}} and tan⁡θ=13\tan \theta = \frac{{1}}{{\sqrt{{3}}}} .
46 Medium
46 of 294
Analyzing +4 | -1
Number of ordered pairs (a,x)(a, x) satisfying the equation sec⁡2(a+2)x+a2−1=0,−π<x<π\sec ^2(a+2) x+a^2-1=0,-\pi < x < \pi is
View answer and explanation
Correct option: C
3
Option C (3) is correct because solving the given equation leads to three ordered pairs that satisfy the conditions.
47 Medium
47 of 294
Analyzing +4 | -1
If S=cos⁡2πn+cos⁡22πn+…+cos⁡2(n−1)πnS=\cos ^2 \frac{\pi}{n}+\cos ^2 \frac{2 \pi}{n}+\ldots+\cos ^2 \frac{(n-1) \pi}{n}, then SS equals
View answer and explanation
Correct option: C
12(n−2)\frac{1}{2}(n-2)
Option C (12(n−2)\frac{1}{2}(n-2)) is correct because the sum simplifies to this expression using trigonometric identities.
48 Medium
48 of 294
Analyzing +4 | -1
If 2sin⁡α1+cos⁡α+sin⁡α=x\frac{2 \sin \alpha}{1+\cos \alpha+\sin \alpha}=x, then 1−cos⁡α−sin⁡αcos⁡α\frac{1-\cos \alpha-\sin \alpha}{\cos \alpha} is equal to
View answer and explanation
Correct option: D
None of these
Option D (None of these) is correct because simplifying the given expression leads to 1−cos⁡α−sin⁡αcos⁡α=−x\frac{{1 - \cos \alpha - \sin \alpha}}{{\cos \alpha}} = -x, which is not among the provided options.
49 Medium
49 of 294
Application +4 | -1
The set of all x∈(−π,π)x \in(-\pi, \pi) satisfying ∣4sin⁡x−1∣<5|4 \sin x-1| < \sqrt{5} is given by
View answer and explanation
Correct option: A
(−π10,3π10)\left(-\frac{\pi}{10}, \frac{3 \pi}{10}\right)
Option A is correct because it represents the interval where the inequality ∣4sin⁡x−1∣<5|4 \sin x - 1| < \sqrt{5} holds true within the specified range of (−π,π)(-\pi, \pi).
50 Medium
50 of 294
Analyzing +4 | -1
If ∣sin⁡xcos⁡xcos⁡xcos⁡xsin⁡xcos⁡xcos⁡xcos⁡xsin⁡x∣=0\left|\begin{array}{lll}\sin x & \cos x & \cos x \\ \cos x & \sin x & \cos x \\ \cos x & \cos x & \sin x\end{array}\right|=0, then the number of distinct real roots of this equation in the interval −π/2<x<π/2-\pi / 2 < x < \pi / 2 is
View answer and explanation
Correct option: C
2
Option C (2) is correct because solving the determinant equation leads to two distinct real roots within the given interval.
51 Medium
51 of 294
Analyzing +4 | -1
If sin⁡  (π  cot⁡  θ)=cos⁡(π  tan⁡  θ)\sin \,\,\left( {\pi \,\,\cot \,\,\theta } \right) = \cos \left( {\pi \,\,\tan \,\,\theta } \right), then
View answer and explanation
Correct option: A
cot⁡  2θ=±  14,   −34\cot \,\,2\theta = \pm \,\,\frac{1}{4},\,\; - \frac{3}{4}
Option A (cot⁡2θ=±14,−34\cot 2\theta = \pm \frac{1}{4}, -\frac{3}{4}) is correct because by using trigonometric identities and solving the equation, we find the possible values of cot⁡2θ\cot 2\theta.
52 Medium
52 of 294
Analyzing +4 | -1
If exp⁡[(sin⁡2x+sin⁡4x+sin⁡6x+…)ln⁡2]\exp ^{\left[\left(\sin ^2 x+\sin ^4 x+\sin ^6 x+\ldots\right) \ln 2\right]} satisfies the equation y2−9y+8=0y^2-9 y+8=0, then the value of cos⁡xcos⁡x+sin⁡x,0<x<π2\frac{\cos x}{\cos x+\sin x}, 0 < x < \frac{\pi}{2}, is
View answer and explanation
Correct option: B
3−12\frac{\sqrt{3}-1}{2}
Option B, 3−12\frac{{\sqrt{{3}}-1}}{{2}}, is correct because it is the simplified value of cos⁡xcos⁡x+sin⁡x\frac{{\cos x}}{{\cos x+\sin x}} when x=π3x = \frac{{\pi}}{{3}}, which is obtained from solving the given equation.
53 Medium
53 of 294
Application +4 | -1
From the identity sin⁡3x=3sin⁡x−4sin⁡3x\sin 3 x=3 \sin x-4 \sin ^3 x it follows that if xx is real and ∣x∣<1|x| < 1, then
View answer and explanation
Correct option: B
(3x−4x3)≤1\left(3 x-4 x^3\right) \leq 1
Option B ((3x−4x3)≤1(3 x-4 x^3) \leq 1) is correct because given ∣x∣<1|x| < 1, we can substitute x=sin⁡θx = \sin \theta, and using the identity sin⁡3θ=3sin⁡θ−4sin⁡3θ\sin 3\theta = 3 \sin \theta - 4 \sin^3 \theta, we know that sin⁡3θ\sin 3\theta is always between -1 and 1, hence less than or equal to 1.
54 Medium
54 of 294
Application +4 | -1
Total number of solutions of cos⁡xcos⁡2xcos⁡3x=14\cos x \cos 2 x \cos 3 x=\frac{1}{4} in [0,π][0, \pi] is
View answer and explanation
Correct option: B
6
Option B (6) is correct because by simplifying the given trigonometric equation, we find that there are 6 solutions in the interval [0, π\pi].
55 Medium
55 of 294
Analyzing +4 | -1
The number of roots of the equation x+2  tan⁡  x=π2x + 2\,\,\tan \,\,x = \frac{\pi }{2} in the interval [0,  2  π]\left[ {0,\,\,2\;\pi } \right], is
View answer and explanation
Correct option: C
3\mathrm{3}
Option C (3) is correct because the graphs of y=tan⁡xy = \tan x and y=π4−x2y = \frac{\pi}{4} - \frac{x}{2} intersect at three points in the given interval.
56 Medium
56 of 294
Analyzing +4 | -1
The equation esin⁡x−e−sin⁡x−4=0e^{\sin x}-e^{-\sin x}-4=0 has
View answer and explanation
Correct option: A
No solution
Option A (No solution) is correct because the equation leads to sin⁡x>1\sin x > 1, which is impossible for real values of x.
57 Medium
57 of 294
Application +4 | -1
The number of values of xx in the interval [0,   5π]\left[ {0,\;\,5\mathrm{\pi }} \right] satisfying the equation 3  sin⁡2x−7  sin⁡  x+2=03\,\,{\sin ^2}x - 7\,\,\sin \,\,x + 2 = 0 is
View answer and explanation
Correct option: C
6
Option D (6) is correct because solving the trigonometric equation and considering the interval [0, 5π\pi] yields 6 solutions.
58 Medium
58 of 294
Application +4 | -1
If tan⁡  θ,  cos⁡  θ,  16  sin⁡  θ\tan \,\,\theta ,\,\,\cos \,\,\theta ,\,\,\frac{1}{6}\,\,\sin \,\,\theta are in G.P., then general value of θ\theta is
View answer and explanation
Correct option: A
2  n   π  ±  π3, n∈Z2\;n\;\,\pi \,\, \pm \,\,\frac{\pi }{3},\,n \in Z
Option A (2  n  π,±,π3, n∈Z2\;n\;\pi \\, \pm \\, \frac{\pi }{3},\,n \in Z) is correct because solving the geometric progression condition leads to cos⁡θ=12\cos \theta = \frac{1}{2}, which gives the general solution θ=2nπ±π3\theta = 2n\pi \pm \frac{\pi}{3}.
59 Medium
59 of 294
Application +4 | -1
sin⁡2π7+sin⁡4π7+sin⁡8π7\sin \frac{2 \pi}{7}+\sin \frac{4 \pi}{7}+\sin \frac{8 \pi}{7} is equal to
View answer and explanation
Correct option: A
72\frac{\sqrt{7}}{2}
Option A (72\frac{{\sqrt{{7}}}}{{2}}) is correct because the sum of sines simplifies to 72\frac{{\sqrt{{7}}}}{{2}} using trigonometric identities and sum-to-product formulas.
60 Medium
60 of 294
Application +4 | -1
A value of θ\theta satisfying sin⁡5θ−sin⁡3θ+sin⁡θ=0\sin 5 \theta-\sin 3 \theta+\sin \theta=0 such that 0<θ<π20 < \theta < \frac{\pi}{2} is
View answer and explanation
Correct option: B
π6\frac{\pi}{6}
Option B (π6\frac{\pi}{6}) is the correct answer because it satisfies the given trigonometric equation within the specified range.
Revision notes and key takeaways

Review TRIGONOMETRIC EQUATIONS in your textbook or class notes, then use this set to check your understanding.

Showing 31-60 of 294 questions
0 /294
0✓ 0✗
0% Accuracy
Type at least 2 characters or jump directly:
🔓

Save your learning progress

Sign in with a free account to save your practice answers and quiz results, then return to them when you revise.