• NEET
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • JEE
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • Class 6-10
      • Class 6th
      • Class 7th
      • Class 8th
      • Class 9th
      • Class 10th
    • View All Options
      • Online Courses
      • Distance Learning
      • Hindi Medium Courses
      • International Olympiad
    • NEET
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • JEE (Main+Advanced)
      • Class 11th
      • Class 12th
      • Class 12th Plus
    • JEE Main
      • Class 11th
      • Class 12th
      • Class 12th Plus
  • Classroom
    • NEET
      • 2025
      • 2024
      • 2023
      • 2022
    • JEE
      • 2025
      • 2024
      • 2023
      • 2022
    • Class 6-10
    • JEE Main
      • Previous Year Papers
      • Sample Papers
      • Result
      • Analysis
      • Syllabus
      • Exam Date
    • JEE Advanced
      • Previous Year Papers
      • Sample Papers
      • Mock Test
      • Result
      • Analysis
      • Syllabus
      • Exam Date
    • NEET
      • Previous Year Papers
      • Sample Papers
      • Mock Test
      • Result
      • Analysis
      • Syllabus
      • Exam Date
      • College Predictor
      • Counselling
    • NCERT Solutions
      • Class 6
      • Class 7
      • Class 8
      • Class 9
      • Class 10
      • Class 11
      • Class 12
    • CBSE
      • Notes
      • Sample Papers
      • Question Papers
    • Olympiad
      • NSO
      • IMO
      • NMTC
  • NEW
    • TALLENTEX
    • AOSAT
  • ALLEN E-Store
    • ALLEN for Schools
    • About ALLEN
    • Blogs
    • News
    • Careers
    • Request a call back
    • Book home demo
Home
Class 9
MATHS
Find the magnitude of angle A, if : si...

Find the magnitude of angle A, if :
`sin^(2)2x+sin^(2)60^(@)=1`

To view this video, please enable JavaScript and consider upgrading to a web browser thatsupports HTML5 video

Text Solution

AI Generated Solution

The correct Answer is:
To solve the equation \( \sin^2(2x) + \sin^2(60^\circ) = 1 \), we will follow these steps: ### Step 1: Substitute the value of \( \sin(60^\circ) \) We know that: \[ \sin(60^\circ) = \frac{\sqrt{3}}{2} \] Thus, we can calculate \( \sin^2(60^\circ) \): \[ \sin^2(60^\circ) = \left(\frac{\sqrt{3}}{2}\right)^2 = \frac{3}{4} \] ### Step 2: Rewrite the equation Now, substitute \( \sin^2(60^\circ) \) into the original equation: \[ \sin^2(2x) + \frac{3}{4} = 1 \] ### Step 3: Isolate \( \sin^2(2x) \) To isolate \( \sin^2(2x) \), subtract \( \frac{3}{4} \) from both sides: \[ \sin^2(2x) = 1 - \frac{3}{4} \] \[ \sin^2(2x) = \frac{1}{4} \] ### Step 4: Take the square root Now, take the square root of both sides: \[ \sin(2x) = \pm \frac{1}{2} \] ### Step 5: Find the angles for \( \sin(2x) = \frac{1}{2} \) The angles for which \( \sin(\theta) = \frac{1}{2} \) are: \[ 2x = 30^\circ + n \cdot 360^\circ \quad \text{or} \quad 2x = 150^\circ + n \cdot 360^\circ \quad (n \in \mathbb{Z}) \] ### Step 6: Solve for \( x \) Dividing by 2, we get: 1. \( x = 15^\circ + n \cdot 180^\circ \) 2. \( x = 75^\circ + n \cdot 180^\circ \) ### Step 7: Consider the principal value For the principal value, we can take \( n = 0 \): - From the first equation: \( x = 15^\circ \) - From the second equation: \( x = 75^\circ \) ### Conclusion The possible values for \( x \) are \( 15^\circ \) and \( 75^\circ \).
Doubtnut Promotions Banner Desktop LightDoubtnut Promotions Banner Desktop DarkDoubtnut Promotions Banner Mobile LightDoubtnut Promotions Banner Mobile Dark

Topper's Solved these Questions

  • TRIGONOMETRICAL RATIOS OF STANDARD ANGLES

    ICSE|Exercise EXERCISE 23(A)|68 Videos
  • TRIGONOMETRICAL RATIOS OF STANDARD ANGLES

    ICSE|Exercise EXERCISE 23(B)|34 Videos
  • TRIGONOMETRICAL RATIOS

    ICSE|Exercise EXERCISE 22(B)|50 Videos
  • TRIGONOMETRY

    ICSE|Exercise TOPIC -4 ( COMPLEMENTARY ANGLES ) (4 MARKS QUESTIONS )|4 Videos

Similar Questions

Explore conceptually related problems

Find the magnitude of angle A, if : sin^(2)2A+sin^(2)60^(@)=1

Find the magnitude of angle A, if : 2sin^(2)A-3sinA+1=0

Find the value of angle A , if : 2 sin A=1

Find the value of angle A , if : 2 sin 2A =1

Find the value of angle A , if : sin 2A = 1

Find the magnitude of angle A, if : 4sinAsin2A+1-2sin2A=2sinA

Find the value of : cos^(2)60^(@)+sin^(2)30^(@)

Find the value of : cos^(2)60^(@)+sin^(2)30^(@)

find the maximum value of f(x) = (sin^(-1) (sin x))^(2) - sin^(-1) (sin x)

In the given figure angle B = 90 ^(@) and angle ADB = x^(@) , Find : (i) sin angle CAB (ii) cos ^(2) C^(@) + sin ^(2) C^(@) (iii) tan x^(@) - cos x^(@) +3 sin x ^(@)

ICSE-TRIGONOMETRICAL RATIOS OF STANDARD ANGLES-EXERCISE 23(C)
  1. Find the magnitude of angle A, if : sin^(2)2x+sin^(2)60^(@)=1

    03:04

    |

  2. Solve the following equations for A, if : 2sinA=1

    00:35

    |

  3. Solve the following equations for A, if : 2cos2A=1

    00:48

    |

  4. Solve the following equations for A, if : sin3A=sqrt(3)/2

    00:44

    |

  5. Solve the following equations for A, if : sec2A=2

    00:43

    |

  6. Solve the following equations for A, if : sqrt(3)tanA=1

    00:40

    |

  7. Solve the following equations for A, if : tan3A=1

    00:46

    |

  8. Solve the following equations for A, if : 2sin3A=1

    00:40

    |

  9. Solve the following equations for A, if : sqrt(3)cot2A=1

    00:45

    |

  10. Calculate the value of A, if : (sinA-1)(2cosA-1)=0

    01:27

    |

  11. Calculate the value of A, if : (tanA-1)(cosec3A-1)=0

    01:38

    |

  12. Calculate the value of A, if : (sec2A-1)(cosec3A-1)=0

    01:40

    |

  13. Calculate the value of A, if : cos3A.(2sin2A-1)=0

    02:10

    |

  14. Calculate the value of A, if : (cosec2A-2)(cot3A-1)=0

    01:35

    |

  15. If 2sinx^(@)-1=0 and x^(@) is an acute angle, find: (i) bsinx^(@)" ...

    01:22

    |

  16. If 4cos^(2)x^(@)-1=0 and 0 le x^(@) le 90^(@), find : x^(@)

    01:25

    |

  17. If 4cos^(2)x^(@)-1=0 and 0 le x^(@) le 90^(@), find : sin^(2)x^(@)+c...

    01:40

    |

  18. If 4cos^(2)x^(@)-1=0 and 0 le x^(@) le 90^(@), find : 1/(cos^(2)x^(@...

    01:44

    |

  19. If 4sin^(2)theta-1=0 and angle theta is less than 90^(@), find the val...

    02:36

    |

  20. If sin3A=1 and 0 le A le 90^(@), find : sin A

    01:14

    |

  21. If sin3A=1 and 0 le A le 90^(@), find : cos 2A

    00:57

    |

Home
Profile
|