You are here:

Advanced Math/Maths-trgnometric ration of allied angles

Advertisement

Expert: Sherry Wallin - 8/4/2011


Question
Prove that
Sin(pi/5)+sin (4pi/5)-sin(11pi/15)-sin(14pi/15)=0

Answer
Dhananjay~

Not sure what there is to prove, you can put this into a calculator and verify it or not. Or you can rewrite the arguments as a sum or difference of know values of the sine function such as pi/4, pi/3, or pi/6 etc...I don't see a way to do the latter and when I  input this equation I actually get
-.0366 which is not equal to 0.

Again before you try to show something is true make sure you can't disprove it.

Math Prof

Advanced Math

All Answers

Answers by Expert:

Ask Experts

Volunteer

Sherry Wallin

Expertise

I can answer most questions up through Calculus and some in Number Theory and Abstract Algebra.

Experience

I have had my Bachelor's Degree since 1987 and have been a teacher since 1988. I earned my Masters Degree in Mathematics May 2010. I have been teaching at the same community college since 2002.

Education/Credentials
I have taught 12 years at the community college level, medical college, and technical college as well as a high school instructor and alternative education instructor and charter school instructor.

Awards and Honors
Master's GPA 3.56 Bachelor's GPA 3.34 Post grad work not degree related GPA 4.0

©2012 About.com, a part of The New York Times Company. All rights reserved.