Search for: If 0≤x≤π/2 and 81sin2x+81cos2x=30, then x is equal If 0≤x≤π/2 and 81sin2x+81cos2x=30, then x is equal Aπ6,π3Bπ3,5π2C5π6,π6D2π3,π3 Fill Out the Form for Expert Academic Guidance!l Grade ---Class 1Class 2Class 3Class 4Class 5Class 6Class 7Class 8Class 9Class 10Class 11Class 12 Target Exam JEENEETCBSE +91 Preferred time slot for the call ---9 am10 am11 am12 pm1 pm2 pm3 pm4 pm5 pm6 pm7 pm8pm9 pm10pm Please indicate your interest Live ClassesBooksTest SeriesSelf Learning Language ---EnglishHindiMarathiTamilTeluguMalayalam Are you a Sri Chaitanya student? NoYes Verify OTP Code (required) I agree to the terms and conditions and privacy policy. Solution:Let 81sin2x=y Than, 81cos2x=811−sin2x=81y−1⇒ 81sin2x+51cos2x=30⇒ y+81y−1=30⇒ y2−30y+81=0⇒ y=3 or, y=27.⇒ 81sin2x=3 or, 27⇒ 34sin2x=31 or, 33⇒ 4sin2x=1 or, 3⇒ sin2x=14 or, 34⇒ sinx=±12 or, ±32⇒x=π6 or, π3 Related content Female Reproductive System Diagram Class 10 NCERT Solutions for Class 11 English Reading Skills Chapter 1 The Portrait of a Lady 50+ Simple GK Questions and Answers for Class 8 Animal Cell Diagram Class 9 Preparation Strategy for NEET Repeaters CBSE Power Sharing Class 10 MCQs Political Science Chapter 1 How to Self Study for NEET Dropper at Home? CBSE Class 9 English Wind Worksheet Viram Chinh in Hindi Worksheets Class 9 with Answers MP Board Class 8 Result 2024 – MPBSE Class 8 Result (Out)