7. Prove the following identities cos 2A a) \frac{cos 2A}{cos A+sin A} = cos A - sin A sin 3? cos 3? b) \frac{sin 3?}{sin ?} - \frac{cos 3?}{cos ?} = 2 sin B cos B c) \frac{sin B}{sin A} - \frac{cos B}{cos A} = 2cosec 2Asin (B - A) d) cosec ? - 2cot 2?cos ? = 2sin ?
Added by Danielle G.
Close
Step 1
To prove sin A cos A = sin A cos A + sin A sin 30 cos 38 = 2 sin θ cos θ, we can start by using the double angle formula for sine: sin 2θ = 2 sin θ cos θ. Using this formula, we can rewrite the equation as: sin A cos A = sin A cos A + sin A sin 30 cos 38 = 2 sin Show more…
Show all steps
Your feedback will help us improve your experience
Breanna Ollech and 59 other Algebra educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Prove the following trigonometric identities:
Bhushan A.
Prove each identity. $$\sin (A+B)+\sin (A-B)=2 \sin A \cos B$$
Identities and Formulas
Sum and Difference Formulas
Prove the identities provided.$$\frac{\tan (a+b)}{\tan (a-b)}=\frac{\sin a \cos a+\sin b \cos b}{\sin a \cos a-\sin b \cos b}$$.
Trigonometric Identities and Equations
Sum and Difference Identities
Recommended Textbooks
Elementary and Intermediate Algebra
Algebra and Trigonometry
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD