Q. 2 B5.0( 5 Votes )

Let us show that:

cos257° + cos233° = 1

Answer :

Given, cos257° + cos2 33°

Need to prove the given equation as one

we know that cos(90 - θ) = sinθ

cos33° = cos(90 - 57)°

= sin57° - - - eq (1)

Substitute eq(1) in the given equation

cos257° + sin257°

we know that, sin2θ + cos2θ = 1

cos257° + sin257° = 1

Hence, proved

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
Trigonometric Identities44 mins
Trick to learn all Trigonometric Formulae28 mins
Solving NCERT Questions on Trigonometric Identities56 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