Jump to
- GST
- Banking
- Shares and Dividends
- Quadratic Equations in One Variable
- Factorization
- Ratio and Proportion
- Matrices
- Arithmetic and Geometric Progression
- Reflection
- Section Formula
- Equation of Straight Line
- Similarity
- Locus
- Circles
- Constructions
- Mensuration
- Trigonometric Identities
- Trigonometric Tables
- Heights and Distances
ML Aggarwal Solutions Class 10 Mathematics Solutions for Trigonometric Identities Exercise 18 in Chapter 18 - Trigonometric Identities
Prev
If 7 sin2 θ + 3 cos2 θ = 4, 0° ≤ θ ≤ 90°, then find the value of θ.
Answer:
Solution:
First we need to split the terms in LHS to make the numerical coefficient equal.
Given,
7 sin2 θ + 3 cos2 θ = 4, 0° ≤ θ ≤ 90°
3 sin2 θ + 3 cos2 θ + 4 sin2 θ = 4
3 (sin2 θ + 3 cos2 θ) + 4 sin2 θ = 4
3 (1) + 4 sin2 θ = 4
4 sin2 θ = 4 – 3
sin2 θ = ¼
Taking square-root on both sides, we get
sin θ = ½
Thus, θ = 30o
Related Questions
Facebook
Whatsapp
Copy Link
Exercises
Chapters
Lido
Courses
Quick Links
Terms & Policies
Terms & Policies
Connect with us on social media!
2022 © Quality Tutorials Pvt Ltd All rights reserved