Q. 12 B5.0( 3 Votes )

# Find θ if cos(2 θ +54o)= sin θ, where (2θ +54o) is an acute angle.

cos(2 θ +54o)= sin θ …(i)

We know that

Sin θ = cos (90° - θ)

So, Eq. (i) become

cos(2 θ +54o) = cos( 90° - θ)

On Equating both the sides, we get

2θ + 54° = 90° - θ

2θ + θ = 90° - 54°

3θ = 36°

θ = 12°

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Trigonometric Identities33 mins
Champ Quiz | Trigonometric Identities33 mins
NCERT | Trigonometric Identities52 mins
Quiz | Task on Trigonometric Ratios46 mins
Trigonometric Identities44 mins
Solving NCERT Questions on Trigonometric Identities56 mins
Algebraic Identities48 mins
Quiz | Practice Important Questions on Trigonometrical Identities46 mins
Quiz on Trigonometric Ratios31 mins
T- Ratios of Specified Angles58 mins
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