trig
posted by John .
Find the exact value of the trigonometric function:
sec(pi/12)
I am not sure how to answer this off the unit circle.

trig 
Reiny
You should know that
sec (pi/12)
= 1/cos(pi/12)
= 1/cos(pi/12)
You might find it "easier" to visualize degrees than radians, if so, the
pi/12 radians = 15º
so we need cos 15º
cos15 = cos(4530) ... (I am dropping the º symbol for easier typing)
= cos45cos30 + sin45sin30
= (√2/2)(√3/2) + (√2/2)(1/2)
= (√6 + √2)/4
and
cos(pi/12) = 4/(√6 + √2)
Respond to this Question
Similar Questions

Alg2/Trig
Find the exact value of the trigonometric function given that sin u = 5/13 and cos v = 3/5. (Both u and v are in Quadrant II.) Find csc(uv). First of all, I drew the triangles of u and v. Also, I know the formula of sin(uv) is sin … 
Trig
Find the exact circular function value for: sec(23pi/6) I know the answer should be: [2sqrt(3)]/3, but I do not understand how to solve the problem. I have a unit circle, but 23pi/6 is not on it, so I don't know how to find the (x,y) 
Pre Calc
use properties of the trigonometric function to find the exact value of each expression. Do no use a calculator. sec (  pi/18) * cos (37 pi)/18 I do not see how to do this problem. Every time I do it out I get a reference angle of … 
Trig
Give the exact value of the trigonometric function: arctan(√3) 
trig
use the unit circle to find the exact value for all the trig functions of è=2ð/3. 
Math
Use the sum or difference identities to find the exact value of each trigonometric function. sec pi/12 Thanks :) 
trig
Find the exact value of the trigonometric function. cot(pi/4 + 16pi) 
trig
Let P be the point on the unit circle U that corresponds to t. Find the coordinates of P and the exact values of the trigonometric functions of t whenever possible. 2pi 3pi/4 5pi/6 Three questions. I think those are supposed to be … 
trig
Let be an angle in standard position and the point (a, b) be the point of intersection of the terminal side of with the unit circle. State the unit circle definitions of the six trigonometric functions. cos = sec = sin = csc … 
Trig
Find the exact value of the trigonometric function given that sin u=3/5 and cos v=8/17. Both u and v are in quadrant II. Tan (u+v)