Q. 13 A3.9( 12 Votes )

If sin 10θ = cos8θ and 10θ is a positive acute angle, let us find the value of tan 9θ.

Given, sin10θ = cos8θ

And 10θ is a positive acute angle

sin10θ = cos8θ

cos(90 - 10θ) = cos8θ

90 - 10θ = 8θ

90 = 18θ

θ = 5

Hence, the value of θ is 5

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Quiz | Task on Trigonometric Ratios46 mins
T- Ratios of Specified Angles58 mins
Quiz on Trigonometric Ratios31 mins
Trigonometric Identities33 mins
Champ Quiz | Trigonometric Identities33 mins
Testing the T- Ratios of Specified Angles57 mins
NCERT | Trigonometric Identities52 mins
Trick to learn all Trigonometric Formulae28 mins
Quiz | Criterion of Similarity of Triangle45 mins
Nature of Roots of Quadratic EquationsFREE Class
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses