## Excel in math and science

### Master concepts by solving fun, challenging problems.

## It's hard to learn from lectures and videos

### Learn more effectively through short, conceptual quizzes.

## Our wiki is made for math and science

###
Master advanced concepts through explanations,

examples, and problems from the community.

## Used and loved by 4 million people

###
Learn from a vibrant community of students and enthusiasts,

including olympiad champions, researchers, and professionals.

## Comments

Sort by:

TopNewestPlease someone prove this – Ashley Shamidha · 2 years, 4 months ago

Log in to reply

– Akshay Bodhare · 2 years, 4 months ago

What are the the restrictions on B and C?Log in to reply

– Ashley Shamidha · 2 years, 3 months ago

ABC is a triangle and A+B+C =180Log in to reply

It's easy to prove \(\frac{\sin A} {\cos B \cos C}=\tan B + \tan C\)

Then after some simplification,you will get the required expression as, \(1+\sec A \sec B \sec C\), which is always greater than 2 in case of triangle. – Akshay Bodhare · 2 years, 3 months ago

Log in to reply