mathslover
  • mathslover
Find the value of : sin 47 (degrees) + sin 61 (degrees) - sin 11 (degrees) - sin 25 (degrees)
Trigonometry
  • Stacey Warren - Expert brainly.com
Hey! We 've verified this expert answer for you, click below to unlock the details :)
SOLVED
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
jamiebookeater
  • jamiebookeater
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
anonymous
  • anonymous
set the calculator to degrees and start pressing buttons
mathslover
  • mathslover
lol @1on1 , that's a shortcut but I do want to do that without *calculator*
anonymous
  • anonymous
Sorry, that will require much more thought from me !

Looking for something else?

Not the answer you are looking for? Search for more explanations.

More answers

mathslover
  • mathslover
No problem! @sasogeek any suggestions, if no then I have only 1 .
mathslover
  • mathslover
Not suggestion but an idea infact.
sasogeek
  • sasogeek
use the calculator to find their actual values and do normal addition... that's if u want to do some work... if not, u may use the calculator to find the whole answer.
mathslover
  • mathslover
hmn quite hard if calculator is not allowed.
sasogeek
  • sasogeek
earlier i thought it was sin(A+B)-sin(A-B) sort of question but it's not, direct solution with the calculator is the way forward :) unless u know those values off the top of ur head xD
mathslover
  • mathslover
xD thanks though
sasogeek
  • sasogeek
i do not wish to confuse you, but you may want to read this, http://www.trans4mind.com/personal_development/mathematics/trigonometry/sumProductCosSin.htm#Sum_of_Sine_and_Cosine
anonymous
  • anonymous
@mathslover Do u knw the Value of Sin18 and cos36
anonymous
  • anonymous
SinA + SinB = 2Sin (A+B)/2 . Cos (A-B)/2...Use this
mathslover
  • mathslover
@Yahoo! and @sasogeek this was my main idea.
mathslover
  • mathslover
Let me try again to find out the answer through the formula of sina + sinb
mathslover
  • mathslover
OK so if I remember the values of : cos 36 degrees and sin 18 degrees then I am getting cos 7 degrees.
mathslover
  • mathslover
cos Here is it how I did that : \[\large{\sin 47 + \sin 61 = 2 \sin 54 \cos 7 }\] ^that theta(s) are in degrees. similarly : \[\large{-(\sin 11 + \sin 25) = -( 2\sin 18 \cos 7)}\] from the above we get : \(2\cos 7 ( \sin 54 - \sin 18 )\) \(2\cos 7 ( 2\cos 36 \sin 18)\) \(4\cos 7 (\frac{\sqrt{5}+1}{4} \times \frac{\sqrt{5}-1}{4})\) \(\cos 7\) That is it! Is it correct? @sasogeek @Yahoo!
anonymous
  • anonymous
Yup...thats wat i also Got
anonymous
  • anonymous
2Sin54.cos7 - 2sin18cos7 2cos7 ( sin54 - sin18) sin54 = cos 36 2cos7(cos36 - sin18) 2cos7( (sqrt5 + 1)/2 - (sqrt5-1)/2) = cos7
anonymous
  • anonymous
Sorry 2cos7( (sqrt5 + 1)/4 - (sqrt5-1)/4)
mathslover
  • mathslover
np, thanks a lot for your help yahoo.
anonymous
  • anonymous
Welcome....)...
anonymous
  • anonymous
To..Be honest..U Did All the Hard Work..)

Looking for something else?

Not the answer you are looking for? Search for more explanations.