SOLUTION: Hi. Please help me prove that this equation is an identity because I really don't know what to do. Thank you! (cot B / sec B - tan B) - (cos B / sec B + tan B) = sin B + csc

Algebra ->  Trigonometry-basics -> SOLUTION: Hi. Please help me prove that this equation is an identity because I really don't know what to do. Thank you! (cot B / sec B - tan B) - (cos B / sec B + tan B) = sin B + csc      Log On


   



Question 602392: Hi. Please help me prove that this equation is an identity because I really don't know what to do. Thank you!
(cot B / sec B - tan B) - (cos B / sec B + tan B) = sin B + csc B

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!




The LCD in the LHS is the product of the two denominators. The two denominators are a conjugate pair, hence the product is the difference of two squares. Apply the LCD:



Use the fact that tangent is sine over cosine, cotangent is the reciprocal of tangent, secant is the reciprocal of cosine, and cosecant is the reciprocal of sine to write:



Simplify the LHS numerator:





Combine the fractions in the LHS denominator:



Use the Pythagorean identity in the LHS denominator:



Finally, apply cosecant is the reciprocal of sine



John

My calculator said it, I believe it, that settles it
The Out Campaign: Scarlet Letter of Atheism