Q. 24 C3.7( 4 Votes )

If , find the value of 1+ cos2 θ.

Answer :



We know that,



Or



Let,


Side opposite to angle θ =AB = 8k


Side adjacent to angle θ =BC = 15k


where, k is any positive integer


Firstly we have to find the value of AC.


So, we can find the value of AC with the help of Pythagoras theorem


(AB)2 + (BC)2 = (AC)2


(8k)2 + (15k)2 = (AC)2


(AC)2 = 64k2+225k2


(AC)2 = 289 k2


AC =289 k2


AC =±17k


But side AC can’t be negative. So, AC = 17k


Now, we will find the cos θ


We know that



Side adjacent to angle θ = BC = 15k


and Hypotenuse = AC = 17k


So,


Now, we have to find the value of 1+ cos2 θ


Putting the value of cos θ, we get






Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Champ Quiz | Trigonometric Identities33 mins
Trigonometric Identities33 mins
NCERT | Trigonometric Identities52 mins
Quiz | Task on Trigonometric Ratios46 mins
Algebraic Identities48 mins
Quiz | Practice Important Questions on Trigonometrical Identities46 mins
Quiz on Trigonometric Ratios31 mins
T- Ratios of Specified Angles58 mins
Trick to learn all Trigonometric Formulae28 mins
Testing the T- Ratios of Specified Angles57 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