# calculus

Find the exact value of the given expression.
(tan17pi/12 - tan pi/4) / (1+tan 17pi/12 tan pi/4)

can you help with this? i got the answer 1/ squareroot 3

1. I assume you used:

tan(A - B) = (tanA - tanB)/( 1 + tanAtanB)

then (tan17pi/12 - tan pi/4) / (1+tan 17pi/12 tan pi/4)
= tan(17π/12 - π/4)
= tan( 7π/6) or tan 210° ---> quad III
= 1/√3

posted by Reiny
2. You are correct!

posted by Reiny

## Similar Questions

1. ### Trigonometry

Find the exact value of tan(a-b) sin a = 4/5, -3pi/2<a<-pi; tan b = -sqrt2, pi/2<b<pi identity used is: tan(a-b)=(tan a-tan b)/1+tan a tan b simplify answer using radicals. (a is alpha, b is beta)
2. ### Pre-Cal

Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. (tan(74°)-tan(14°))/(1+tan(74°)tan(14°)) =__________ Find it's exact value (not decimal form) =__________ Note: A
3. ### Trigonometry

Hello, everyone: I am working on finding the exact values of angles that are less common and are therefor not found easily on the Unit Circle (at least, they are not labeled). For example, the problem I am asking about is: 10)
4. ### Math

Use an addition or subtraction formula to write the expression as a trigonometric function of one number, and then find its exact value. (tan(π/2)+tan((2π)/3)) / (1-tan(π/2)tan((2π)/3)) Answer=__________ Exact
5. ### PreCalculus

Hi I need some assistance on this problem find the exact value do not use a calculator cot[(-5pi)/12] Here is my attempt RT = square root pi = 3.14...
6. ### trig

h t t p : / / i m g 4 0 . i m a g e s h a c k . u s / c o n t e n t . p h p ? p a g e = d o n e& l = i m g 4 0 / 1 4 8 / a s d a s d y e . j p g & v i a = m u p l o a d (def of tan theta = a^-1 o)a = o opposite = adjacent tan
7. ### Math-Trigonometry

Show that if A, B, and C are the angles of an acute triangle, then tan A + tan B + tan C = tan A tan B tan C. I tried drawing perpendiculars and stuff but it doesn't seem to work? For me, the trig identities don't seem to plug in
8. ### Math- Precalculus

Write the expression as the sine, cosine, tangent of an angle (in radians.) (tan(pi/5)-tan(pi/3))/(1+tan(pi/5)tan(pi/3))
9. ### Trig

Can someone check my answers so far? 1. Find the exact value of tan(-3ð) Answer: tan(-3ð) = tan (-3 + 2ð) = tan (-ð) = tan (-ð + 2ð) = tan(ð) = sin (ð)/cos(ð) = (0)/(-1) = 0 Exact value is 0 2. Solve triangleABC is C = 90
10. ### Integration

Intergrate ¡ì sec^3(x) dx could anybody please check this answer. are the steps correct? thanks. = ¡ì sec x d tan x = sec x tan x - ¡ì tan x d sec x = sec x tan x - ¡ì sec x tan^2(x) dx = sec x tan x + ¡ì sec x dx - ¡ì

More Similar Questions