Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas 2020
Exam
NTA Abhyas
Year
2020
Subject
Mathematics
Chapter
Trigonometric Equations

NTA Abhyas 2020 · Mathematics · Trigonometric Equations

If A = \ θ: 2 ^ 2 θ + sin θ ≤ 2\ and B = \ θ: (π)/(2) ≤ θ ≤...

If A={θ:2cos⁡2θ+sinθ≤2}A = \left\{\theta: 2\cos^{2} \theta + sin \theta \le 2\right\} and B={θ:π2≤θ≤3π2}B = \left\{\theta: \dfrac{\pi}{2} \le \theta \le \dfrac{3\pi}{2}\right\}, then A∩BA \cap B is equal toIf A = \ θ: 2 ^ 2 θ + sin θ ≤ 2\ and B = \ θ: (π)/(2) ≤ θ ≤ (3π)/(2)\ , then A B is equal to

Options

  1. A{θ:π2≤θ≤5π6}\left\{\theta: \dfrac{\pi}{2} \le \theta \le \dfrac{5\pi}{6}\right\}
  2. B{θ:π≤θ≤3π2}\left\{\theta: \pi \le \theta \le \dfrac{3\pi}{2}\right\}
  3. C\left\{\theta: \dfrac{\pi}{2} \le \theta \le \dfrac{5\pi}{6}\right\}~or& \left\{\theta: \pi \le \theta \le \dfrac{3\pi}{2}\right\}
  4. D{θ:3π4≤θ≤7π4}\left\{\theta: \dfrac{3\pi}{4} \le \theta \le \dfrac{7\pi}{4}\right\}

Correct answer

C. \left\{\theta: \dfrac{\pi}{2} \le \theta \le \dfrac{5\pi}{6}\right\}~or& \left\{\theta: \pi \le \theta \le \dfrac{3\pi}{2}\right\}

Step-by-step solution

2 - 2\sin^{2} \theta + sin \theta \le 2<br/><br />2\sin^{2} \theta - sin \theta \ge 0<br/><br />sin \theta\left(2sin \theta - 1\right) \ge 0<br/>CaseI:<br />Case I:sin \theta \ge 0, sin \theta \ge \dfrac{1}{2}<br/><br />⇒ sin \theta \ge \dfrac{1}{2} ⇒ \theta \in \left[\dfrac{\pi}{2}, \dfrac{5\pi}{6}\right]<br/><imgsrc="https://cdn−question−pool.getmarks.app/ntaabhyas/jeemain/images/345678iugfdfghjkzjzjzjz.JPG"style="max−width:100<br /><img src="https://cdn-question-pool.Quantrex.app/nta_abhyas/jee_main/images/345678iugfdfghjkzjzjzjz.JPG" style="max-width:100%; object-fit:contain" style="width: 200px; height: 137px;" /><br />Case II:sin \theta \le 0, sin \theta \le \dfrac{1}{2}<br/><br />⇒ sin \theta \le 0<br/><br />⇒ \theta \in \left[\pi, \dfrac{3\pi}{2}\right]<br/><br />⇒ A \cap B = \left\{\theta: \dfrac{\pi}{2} \le \theta \le \dfrac{5\pi}{6}\right\}or{θ:π≤θ≤3π2}or \left\{\theta: \pi \le \theta \le \dfrac{3\pi}{2}\right\}
Practice Trigonometric Equations on Quantrex Academy →

More from Trigonometric Equations

Match each entry in List-I to the correct entry in List-II and choose the correct option.… JEE Advanced 2026Passage: Consider the curve C_1 given by y = e^ -x for x ∈ [0, 10π] , and the curve C_2… JEE Advanced 2026Let S = \ θ ∈ (-2π, 2π) : θ + 1 = 3 θ\ . Then ∑_ θ ∈ S θ is equal to: JEE Main 2026If S = \ θ ∈ [-π, π] : θ (5θ)/(2) = 7θ (7θ)/(2)\ , then n(S) is equal to _______. JEE Main 2026Let S = \ x ∈ [-π, π] : x ( x + x) = a, a ∈ ℤ\ . Then n(S) is equal to : JEE Main 2026The number of elements in the set \ x ∈[0,180^ ∘ ]: (x+100^ ∘ )= (x+50^ ∘ ) x (x-50^ ∘ )\… JEE Main 2026Number of solutions of 3 2 θ+8 θ+3 3 =0, θ ∈[-3 π, 2 π] is: JEE Main 2026The number of solutions of the equation 2 θ (θ)/(2)+ (5 θ)/(2)=2 ^3 (5 θ)/(2) in… JEE Main 2025If for θ ∈[-(π)/(3), 0] , the points (x, y)=(3 (θ+(π)/(3)), 2 (θ+(π)/(6))) lie on x y+α… JEE Main 2025If 10 ^4 θ+15 ^4 θ=6 , then the value of 27 cosec^6 θ+8 ^6 θ 16 ^8 θ is: JEE Main 2025The number of solutions of equation (4- 3 ) x -2 3 ^2 x=- 4 1+ 3 , x ∈[-2 π, (5 π)/(2)] is JEE Main 2025The number of solutions of the equation 2 x+3 x=π, x ∈[-2 π, 2 π]-\ ± (π)/(2), ± (3… JEE Main 2025If θ ∈[-(7 π)/(6), (4 π)/(3)] , then the number of solutions of 3 cosec^2 θ-2( 3 -1)… JEE Main 2025If θ ∈[-2 π, 2 π] , then the number of solutions of 2 2 ^2 θ+(2- 6 ) θ- 3 =0 , is equal… JEE Main 2025The sum of all values of θ ∈[0,2 π] satisfying 2 ^2 θ= 2 θ and 2 ^2 θ=3 θ is JEE Main 2025Let f: ℝ arrow ℝ be a function defined by f(x)=\ array cc x^2 ((π)/(x^2)), & if x ≠ 0 0… JEE Advanced 2024 Full Trigonometric Equations list Trigonometric Equations JEE Maths PYQsJEE Mathematics PYQs All NTA Abhyas JEE Main PYQs