PreCalc : Find the Exact Value of the Expression
posted by Phil HELP NEEDED ASAP .
Find the exact value of the expression without a calculator:
sin(3π/4+5π/6)
I've done:
sin(9π/12 + 10π/12)
=sin(19π/12)
What do I do now? Im confused if that would just be the answer or what? Wouldnt the answer be numerical?

sin(19π/12) = sin(3π/2 + π/12) = cos(π/12)
Now use the halfangle formula to evaluate that. 
Thank you!

tan(15)
Respond to this Question
Similar Questions

Math
Evaluate *Note  We have to find the exact value of these. That I know to do. For example sin5π/12 will be broken into sin (π/6) + (π/4) So... sin 5π/12 sin (π/6) + (π/4) sin π/6 cos π/4 + cos … 
Math 2nd question
Express as a single sine or cosine function (note: this is using double angle formulas) g) 8sin^2x4 I just don't get this one. I know it's got something to do with the 12sin^2x double angle formula. It's the opposite though? 
Math integrals
What is the indefinite integral of ∫ [sin (π/x)]/ x^2] dx ? 
Precalculus
Use one of the identities cos(t + 2πk) = cos t or sin(t + 2πk) = sin t to evaluate each expression. (Enter your answers in exact form.) (a) sin(19π/4) (b) sin(−19π/4) (c) cos(11π) (d) cos(53π/4) … 
Trig Help!
Question: Trying to find cos π/12, if cos π/6 = square root 3 over 2, how to find cos π/12 using DOUBLE angle formula? 
Math, please help
Which of the following are trigonometric identities? 
Math
Find all the possible values of the expression. sin^1 (square root3/2) Ans: 4π/3 + (2π)n 5π/3 + (2π)n 
precalc
Given that sec 3π/10 ≈ 17/10 and csc 3π/10 ≈ 17/14, find the following: 1. sin 3π/10 ≈ 14/17 (is this one correct) 2. csc 43π/10 ≈ 3. sec 2π/10 ≈ 4. cot 12π/10 ≈ 5. … 
calc 1
f(t)=cos(πt/4) finding velocity i got π/4sin(πt/4) then i had to find velocity after 3 sec which is v'(3)=π/4sin(π(3)/4) = π/4sin(π√2/2) (π) (π√2)/4 x 2 = 1/8√2 ft/s … 
precalc
Find the exact value of each expression, if it exists: the 1 are representing the inverse functions! (a) sin 1 (√2/2) (b) cos−1 (−1) (c) sin( sin−1 (π)) (d) cos−1(cos(−4π/ …