# trig

Find the exact value of the trigonometric function:
sec(-pi/12)

I am not sure how to answer this off the unit circle.

1. 👍
2. 👎
3. 👁
1. 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

so we need cos 15º

cos15 = cos(45-30) ... (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)

1. 👍
2. 👎

## Similar Questions

1. ### Trig.

I really need help so please help. write the first trigonometric function in terms of the second trigonometric function. sec x; tan x

2. ### Trig

Find the exact values of the six trigonometric functions 0 if the terminal side of 0 in standard position contains the points(-5,-4). (0 is not the number zero I don't know what its called) I have to find r first. r=sqrt x^2+y^2

3. ### math

use even and odd properties of the trigonometric functions to find the exact value of the expression. sin(−π/6)

4. ### Pre-Calc

1) Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. cos 12° cos 18° − sin 12° sin 18° And Find its exact value. 2) Use an Addition or Subtraction Formula to write the

1. ### Pre-Calc

I am really struggling with how to do these problems, I posted them a few minutes ago but the answers/work shown was incorrect. 1) a) Use an Addition or Subtraction Formula to write the expression as a trigonometric function of

2. ### 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

3. ### Math

sec 7pi/4 without a calculator Find the exact answer

4. ### math

Sketch a right triangle corresponding to the trigonometric function of the acute angle θ. Use the Pythagorean Theorem to determine the third side and then find the other five trigonometric functions of θ. cot(θ) = 3 sin(θ)=

1. ### Pre-Calculus

The exponential function y(x)=Ce^ax satisfies the conditions y(0)=6 and y(1)=7. (a) Find the constants C and a. Enter the exact value of a. (b) Find y(2). Enter the exact answer. Simplify the answer so it does not contain any

2. ### Math

Find the values of the six trigonometric functions of θ. (If an answer is undefined, enter UNDEFINED.) Function Value: csc(θ) = 4 Constraint: cot(θ) < 0 1) sin(θ)= 2) cos(θ)= 3) tan(θ)= 4) csc(θ)= 5) sec(θ)= 6) cot(θ)=

3. ### Trigonometry help

If sin(x) = 1/3 and sec(y) = 13/12 , where x and y lie between 0 and π/2, evaluate the expression using trigonometric identities. (Enter an exact answer.) sin(x + y)