trig
posted by Anonymous .
use sum or difference identities to find the exact value of the trigonometric function: tan 345
please show work, i cant figure out what im doing wrong!

tan(345)?
Tan(2*345)=tan(690)=tan(72030)=tan(30)
tan(2*345)= 2*tan(345)/(1tan^2(345)
lets call tan(345) Y
tan(30)=2y/(1y^2)
Call Tan(30) X
xXY^2=2Y
XY^2+2Yx=0
use the quadratic to solve for y in terms of X
(tan(30)=1/sqrt3) 
prove that tan20 tan30 tan40 = tan 10
Respond to this Question
Similar Questions

Trigonometric
Find the exact value of cos7(pi)/12 using sum and/or difference identities. 
Math
Use the given function values and trigonometric identities (including the relationship between a trigonometric function and its cofunction of a complementary angle) to find the indicated trigonometric functions. sec Q = 5 tan = 2sqrt6 … 
trig
please help me. use trig. identities to find the exact value. tan 25° + tan 5° / 1 tan 25° tan 5° 
trig
please help me. use trig. identities to find the exact value. tan 25° + tan 5° / 1 tan 25° tan 5° 
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)) / (1tan(π/2)tan((2π)/3)) Answer=__________ Exact value … 
Math
Use the sum or difference identities to find the exact value of each trigonometric function. sec pi/12 Thanks :) 
TRIG/ALGEBRA
1) Find the exact value. Use a sum or difference identity. tan (15 degrees) 2) Rewrite the following expression as a trigonometric function of a single angle measure. cos 3x cos 4x  sin 3x sine 4x 
Math Trig
1. Determine the exact value of cos^1 (pi/2). Give number and explanaton. 2. Determine the exact value of tan^1(sq. root 3). with explanation. 3. Determine exact value of cos(cos^1(19 pi)). with explanation. 4. Determine the exact … 
trig
Use a sum or difference identity to find the exact value. tan 25deg + tan 5deg / 1tan 25deg tan 5deg 
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)