You are here:

Calculus/help in trignometry

Advertisement

Expert: - 4/15/2008


Question
QUESTION: radian-degree converstion
@rad=πrad/180(75)=5π/12=1.31
OK the question is how did the answer become 5π/21 I mean when I press the calculator it gave me 1.308 which is 1.31 so how or what does 5π/21 come from I need to know to understand the chapter.

ANSWER: I get 1.308996939 for 5pi/12, which you stated, which does round to 1.31.  

@rad=πrad/180(75)=5π/12=1.31

What is the (75) here for?  radians = degrees * pi / 180
and 5*pi/12 = 1.308996939.  What's the question?

180 degrees is the same as pi radians, so if d is degrees and r is radians, d/180 = r/pi = half a circle.

Is this helpful at all?

---------- FOLLOW-UP ----------

QUESTION: no it is not helpfull /i asked
pi/180X(75) so how did pi/180x(75) become 5pi/21
I mean how did that happen explain becoase I might need to know this for graphing.

Answer
I'm sorry that I responded with the wrong answer.  Thank you for explaining more clearly the answer that was needed.

Note that 75=5*15 and 180=12*15, so 75/180 is the same as 5/12.  The 21 must have been a type since it was really suppose to be 12 from what was given to me at the start.

I hope this explains it well enough.

Calculus

All Answers

Answers by Expert:

Ask Experts

Volunteer

Scotto

Expertise

Any kind of calculus question you want. I also have answered some questions in Physics (mass, momentum, falling bodies), Chemistry (charge, reactions, symbols, molecules), and Biology.

Experience

Experience in the area: I have tutored students in all areas of mathematics for over 25 years. Education/Credentials: BSand MS in Mathematics from Oregon State University, where I completed sophomore course in Physics and Chemistry. I received both degrees with high honors. Awards and Honors: I have passed Actuarial tests 100, 110, and 135.

Publications
Maybe not a publication, but I have respond to well oveer 7,500 questions on the PC. Well over 2,000 of them have been in calculus.

Education/Credentials
I aquired well over 40 hours of upper division courses. This was well over the number that were required. I graduated with honors in both my BS and MS degree from Oregon State University. I was allowed to jump into a few junior level courses my sophomore year.

Awards and Honors
I have been nominated as the expert of the month several times. All of my scores right now are at least a 9.8 average (out of 10).

Past/Present Clients
My past clients have been students at OSU, students at the college in South Seattle, referals from a company, friends and aquantenances, people from my church, and people like you from all over the world.

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