Math (Calc)
posted by Bryan .
Find the Exact value of Pi/24.
I'm not sure whether to use a halfangle formula or a difference/sum of angles formula.

I don't think any formula is necessary. I believe it just wants the equivalent angle measurement. In that case, pi is 180 degrees. Therefore, pi/24 would be 180/24, which can be simplified. I'm not 100% sure if this is the form they are requesting, though.

They want it in this form.
sin (pi/6) is 1/2
So sin (pi/240 is ______ 
Well, converting to degrees it is 7.5 degrees
that makes me think right off that 30 degrees divided by two is 15 degrees and 15 degrees divided by two is 7.5 degrees
so I have a sneaking suspicion that if I divide 30 degrees by two twice I will get pi/24
but 30 degrees is pi/6
and we know that sin(pi/6) = 1/2
and cos pi/6 = sqrt3/2
All of which is my hard way of saying that we can get there from
pi/24 = (1/2)(1/2) (pi/6)
and we know the sin and cos of pi/6 exactly 
I think Bryan did not copy the question correctly. I agree with Michael that the way it stands it is not much of a question.
pi/24 cannot be stated "exactly" since pi is a transcendental number
Probably the question said
find the exact value of sin pi/24 or
find the exact value of cos pi/24
I will do the cos pi/24
As Damon noted pi/24 radians is 7.5º, or 1/2 of 1/2 of 30º whose cosine we know to be √3/2
so starting with cos 30 = 2cos^2 15º  1
if got cos 15º = √(√3+2)/2
and then cos 15º = 2cos^2 7.5º  1
√(√3+2)/2 = 2cos^2 7.5º  1
which after "simplifying" gave me
cos 7.5º = √(√(√3 + 2) + 2)/2
cos pi/24 = √(√(√3 + 2) + 2)/2
check
cos 7.5º = .9914448
Right Side of my equation = .9914448 
so pi/24 = cos^1[ √(√(√3 + 2) + 2)/2 ]
I guess :) 
certainly, of course, lol

Ya sorry it was sin (pi/24)
Respond to this Question
Similar Questions

Trig
Use the half angle formula to find the exact value of tan 7 pie/8 
Math
Use the half formula to find the exact value of the expression sin 22.5 
Calculus
I had this on a test: Use the halfangle formula to find the exact value of the expresseion: sin 22.5 degrees my answer  1/2 sqrt2  sqrt 2 was wrong 
trig
Use a halfangle formula to find the exact value of cos 5ð/12 
Math
Use a half angle formula to determine the exact value of sin 7(pi)/12. 
Math Analysis
Use the halfangle formula to find the exact value of cos(x/2) when tanx = 5/8 and x is in quadrant IV. ( is a radical) ==> I got sqrt((89 + 8sqrt(89))/178). Is this correct? 
trig
use a half angle formula to find the exact value of cos 75 degree 
Calculus
find the exact value of sin 11pi/12 using the sum or difference formula. 
pre calc
use an appropriate halfangle formula to find the exact value ofthe expression. tan22.5 write the product as a sum sinxsin5x write the sum as a product sin2xsin7x 
PreCalc
Find the exact value of sin345 degrees using a sum or difference formula. I got (sqrt6 + sqrt2)/4. Is this right?