Find the exact value of cos 8 degrees cos 38 degrees + sin 8 degrees sin 38 degrees
108,643 results
Trig
Find sin(s+t) and (st) if cos(s)= 1/5 and sin(t) = 3/5 and s and t are in quadrant 1. =Sin(s)cos(t) + Cos(s)Sin(t) =Sin(1/5)Cos(3/5) + Cos(1/5)Sin(3/5) = 0.389418 Sin(st) =sin(s)cos(t)  cos(s)sin(t) =sin(3/5)cos(1/5)  cos(1/5)sin(3/5) =Sin3/5

Trig(3 all with work)
1)Find the exact value of cos 105 by using a halfangle formula. A)sqrt 2  sqrt 3 /2 B)sqrt 2  sqrt 3 /2 C)sqrt 2 + sqrt 3 /2 D)sqrt 2 + sqrt 3 /2 cos 105 cos 105 = cos 210/2 sqrt 1 + 210/2 sqrt 1 + sqrt 3/2 /2 sqrt 2 + sqrt 3/2 which is D 2)Find the

PreCal (Trig) Help?
The following relationship is known to be true for two angles A and B: cos(A)cos(B)sin(A)sin(B)=0.957269 Express A in terms of the angle B. Work in degrees and report numeric values accurate to 2 decimal places. So I'm pretty lost on how to even begin

math
Can you please check my work. A particle is moving with the given data. Find the position of the particle. a(t) = cos(t) + sin(t) s(0) = 2 v(0) = 6 a(t) = cos(t) + sin(t) v(t) = sin(t)  cos(t) + C s(t) = cos(t)  sin(t) + Cx + D 6 = v(0) = sin(0) cos(0)

Calculus
Find the velocity, v(t), for an object moving along the xaxis in the acceleration, a(t), is a(t)=cos(t)sin(t) and v(0)=3 a) v(t)=sin(t) + cos(t) +3 b) v(t)=sin(t) + cos(t) +2 c) v(t)= sin(t)  cos(t) +3 d) v(t)= sin(t)  cos(t) +4

Calculus 12th grade (double check my work please)
1.)Find dy/dx when y= Ln (sinh 2x) my answer >> 2coth 2x. 2.)Find dy/dx when sinh 3y=cos 2x A.2 sin 2x B.2 sin 2x / sinh 3y C.2/3tan (2x/3y) D.2sin2x / 3 cosh 3yz...>> my answer. 2).Find the derivative of y=cos(x^2) with respect to x. A.sin (2x) B.2x

Algebra
In a right triangle, one angle measures x degrees where sin x degrees= 5/8. What is the value of cos (90 degreesx) ?

Precalculus
An airplane is flying on a bearing of 285 degrees at 480 mph. A wind is blowing with the bearing 265 degrees at 30? a. find the component from of the velocity of the airplane b. find the actual speed and direction of the airplane 485 sin 75 degrees 485

trigonometry
Find all the angles between 0 degrees and 360 degrees which satisfy the equations a. 8 cos x sin x = sin x b. 5 tan^2 y + 5 tan y = 2 sec^2 y.

trig math 30
Find the exact value of cos 8 degrees cos 38 degrees + sin 8 degrees sin 38 degrees

math
1)In triangle ABC, C=60 degrees, a=12, and b=5. Find c. A)109.0 B)10.4 C)11.8 D)15.1 I chose B 2)Which triangle should be solved by beginning with the Law of Cosines? A)A=115 degrees, a=19, b=13 B)A=62 degrees, B=15 degrees, b=10 C)B=48 degrees, a=22, b=5

Algebra II
1) Find the exact value of cos 105 degrees by using a halfangle formula. 2)Find the solution of sin 2theta = cos theta if 0 degrees

Algebra II
Find the exact value of sin(theta/2) if cos theta = 2/3 and 270 degrees

math;)
Show that sin(x+pi)=sinx. So far, I used the sum formula for sin which is sin(a+b)=sin a cos b+cos a sin b. sin(x+pi)=sin x cos pi+cos x sin pi I think I am supposed to do this next, but I am not sure. sin(x+pi)=sin x cos x+sin pi cos pi If that is right

Trigonometry
Write the expression as a trigonometric function of one number. (cos 20 degrees)(cos 70 degrees)+(sin 20 degrees)(sin 70 degrees)

Trigonometry  Identities
If tan 2x =  24/7, where 90 degrees < x < 180 degrees, then find the value of sin x+ cos x. I applied various identities and tried manipulating the problem to get sin x + cos x = sin(arctan(24/7)/2) + cos(arctan(24/7)/2) I also played around with the

Math
1. Find the value of Sin^1(1/2) a. 30 degrees b. 30 degrees c. 150 degrees d. 330 degrees 2. Find the exact value of cos(420 degrees) a. 1/2 b. 1/2 c. sqrt of 3/2 d. sqrt of 3/2 3. p(9/41, 40/41) is located on the unit circle. Find sin theta. a.

Trig
If angle A is 45 degrees and angle B is 60 degrees. Find sin(A)cos(B), find cos(A)sin(B), find sin(A)sin(B), and find cos(A)cos(B) The choises for the first are: A. 1/2[sin(105)+sin(345)] B. 1/2[sin(105)sin(345)] C. 1/2[sin(345)+cos(105)] D.

trigonometry
What is the single trigonometric function of (Cos 20 degrees) (Cos 30 degrees)(Sine 20 degress) (Sin 30 degrees)

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

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) (e) tan(−3π/4) (f) cos(π/4) (g) sec(π/6+ 2π)

Trigonometry
Solve the equation for solutions in the interval 0

Trigonometry
Please review and tell me if i did something wrong. Find the following functions correct to five decimal places: a. sin 22degrees 43' b. cos 44degrees 56' c. sin 49degrees 17' d. tan 11degrees 37' e. sin 79degrees 23'30' f. cot 19degrees 0' 25'' g. tan

Trig
What is the exact value of cos 40 degrees cos 50 degrees minus sin 40 degrees sin 50 degrees do you know the formula cos(A+b) = cosAcosB  sinAsinB now compare it with your cos 40 degrees cos 50 degrees minus sin 40 degrees sin 50 degrees

trig
Evaluate sin(29 degrees)cos(31 degrees) + cos(29 degrees)sin(31 degrees) exactly, without using a calculator.

Calculus
Find the velocity, v(t), for an object moving along the xaxis if the acceleration, a(t), is a(t) = cos(t)  sin(t) and v(0) = 3. v(t) = sin(t) + cos(t) + 3 v(t) = sin(t) + cos(t) + 2 v(t) = sin(t)  cos(t) + 3 v(t) = sin(t)  cos(t) + 4

math
Express each of the following in terms of another angle between 0 degrees and 180 degrees a. sin 50 degrees b. sin 150 degrees c. cos 45 degrees d. cos 120 degrees please explain to me how to answer this question you don't have to answer it , but please

math
Find each value if cos A=12/13 with 0 (degrees)

trig
How do you express in terms of angles less than 90 degrees? sin 120 degrees cos 150 degrees tan 280 degrees

Trig hep, please? Thank you!
1. Find the exact value of sin(195(degrees)) 2. If cot2(delta)=5/12 with 0(

math
Find the exact value of 1. tan 75 degrees 2. Cos 15 degrees 3. Sin 105 degrees

Spherical Trigonometery
I am trying to apply the formula cos c = cos a x cos b + sin a x sin b x cos C to find the length of c in my spherical triangle. I am working with 2 examples in a book in which the answers are given. In the first example all the sines & cosines calculated

Trig
Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < 2pi Find: sin (v + u) cos (v  u) tan (v + u) First compute or list the cosine and sine of both u and v. Then use the combination rules sin (v + u) = sin u cos v + cos v sin u. cos (v  u) = cos u

MATH
Which expression is the is a fourth root of 1+i sqrt3 1. the fourth root of 2 (cos(280 degrees)+i sin(280 degrees)) 2.the fourth root of 2 (cos(30 degrees)+i sin(30 degrees)) 3.the fourth root of 2 (cos(60 degrees)+i sin(60 degrees)) 4.the fourth root of

tigonometry
expres the following as sums and differences of sines or cosines cos8t * sin2t sin(a+b) = sin(a)cos(b) + cos(a)sin(b) replacing by by b and using that cos(b)= cos(b) sin(b)= sin(b) gives: sin(ab) = sin(a)cos(b)  cos(a)sin(b) Add the two equations:

trig
give exact value of cos 75 degrees. give exact value sin 15 degrees. give exact value sin 225 degrees. You will have to use the addition relations here. Notice 75 is 30 +45, 15 is 4530, and 225 is 180 + 45. I will be happy to critique your work.

Mathematics  Trigonometric Identities
Let y represent theta Prove: 1 + 1/tan^2y = 1/sin^2y My Answer: LS: = 1 + 1/tan^2y = (sin^2y + cos^2y) + 1 /(sin^2y/cos^2y) = (sin^2y + cos^2y) + 1 x (cos^2y/sin^2y) = (sin^2y + cos^2y) + (sin^2y + cos^2y) (cos^2y/sin^2y) = (sin^2y + cos^2y) + (sin^2y +

Trig(continued)
2)Find the solution of sin2 theta = cos theta if 0 < theta < 180 A)30 degrees and 90 degrees B)30 degrees and 150 degrees C)30 degrees, 90 degrees, 150 degrees D)0 degrees, 90 degrees, and 150 degrees sin2 theta = cos theta sin2 theta  1 = 0 (sin theta +

precalc/Trig
Assume we know the following: cos(22.5 degrees)= sqrt(2+sqrt2)/2 sin(22.5 degrees)=sqrt(2sqrt2)/2 cos(18 degrees)=sqrt((sqrt5+5)/8) sin(18 degrees)=(sqrt51)/4 What is: Sin(82.5 degrees) cos(82.5 degrees) sin(12 degrees) cos(12 degrees)

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/ 3)) (e) tan−1 (tan(0.6)) (f) cos−1(

trig help much appreciated! :))
1. Find the complete exact solution of sin x = . 2. Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. 3. Solve tan2 x + tan x – 1 = 0 for the principal value(s) to two decimal places. 4. Prove that tan2 – 1 + cos2

trig
Assume that we know sin(18 degrees)=(sqrt(5)1)/4, cos(18 degrees)=(sqrt(sqrt(5)+5))/8, find sin(42 degrees) exactly, without using a calculator. Also find cos(42 degrees).

Pre Calculus
Use one of the identities cos(t + 2ðk) = cos t or sin(t + 2ðk) = sin t to evaluate each expression. (Enter your answers in exact form.) (a) sin(17ð/4) (b) sin(−17ð/4) (c) cos(17ð) (d) cos(45ð/4) (e) tan(−3ð/4) (f) cos(7ð/4) (g) sec(ð/6+2ð)

Pre Calculus
Use one of the identities cos(t + 2ðk) = cos t or sin(t + 2ðk) = sin t to evaluate each expression. (Enter your answers in exact form.) (a) sin(17ð/4) (b) sin(−17ð/4) (c) cos(17ð) (d) cos(45ð/4) (e) tan(−3ð/4) (f) cos(7ð/4) (g) sec(ð/6+2ð)

Math
Solve this equation algebraically: (1sin x)/cos x = cos x/(1+sin x)  I know the answer is an identity, and when graphed, it looks like cot x. I just don't know how to get there. I tried multiplying each side by its conjugate, but I still feel stuck.

Math
1) If the Sin(70 degrees)= Cos(A), what must A be? 2) Why is the Sine of 10 degrees the same as the Cosine of 80 degrees?

Algebra II
Multiple Choice (theta) means the symbol 0 with the dash in it. 1.)Which expression is equivalent to tan(theta)(sec(theta))/(sin(theta))? A.)cot(theta) B.)cot(theta) C.)tan(theta)cot(theta) D.)tan(theta)sec^2(theta) 2.)Find the exact value of:cos 375

trig
Reduce the following to the sine or cosine of one angle: (i) sin145*cos75  cos145*sin75 (ii) cos35*cos15  sin35*sin15 Use the formulae: sin(a+b)= sin(a) cos(b) + cos(a)sin(b) and cos(a+b)= cos(a)cos(b)  sin(a)sin)(b) (1)The quantity = sin(14575) = sin

TRIG!
Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6 x=1  (3/4)sin^2 2x work on one side only! Responses Trig please help!  Reiny, Monday, February 23, 2009 at 4:27pm LS looks like the sum of cubes sin^6 x + cos^6 x = (sin^2x)^3 +

math
PLEASE HELP ME WITH THIS TRIGONOMETRY QUESTION!!? Edit Express each of the following in terms of another angle between 0 degrees and 180 degrees a. sin 50 degrees b. sin 150 degrees c. cos 45 degrees d. cos 120 degrees Update: we have not yet learnt it in

trigonometry (please double check this)
Solve the following trig equations. give all the positive values of the angle between 0 degrees and 360 degrees that will satisfy each. give any approximate value to the nearest minute only. 1. sin2ƒÆ = (sqrt 3)/2 2. sin^2ƒÆ = cos^2ƒÆ + 1/2 3. sin 2x

Trigonometry
I have some trigonometric equations to do, but I'm pretty lost, and I have to get them done in a timely fashion, so any help would be much appreciated. "Solve the following trig equations. Give all the positive values of the angle between 0 degrees and 360

math
find the exact value of [sec(30 degrees) cot 120 degrees]/1cosec^2(45 degrees) Find the exact value of [sin^2(355 degrees) + cos^2 (355 degrees)]/ tan^2 (30 degrees)

algebra
Can someone please help me do this problem? That would be great! Simplify the expression: sin theta + cos theta * cot theta I'll use A for theta. Cot A = sin A / cos A Therefore: sin A + (cos A * sin A / cos A) = sin A + sin A = 2 sin A I hope this will

Math
Find the exact value of cos 1 degree + cos 2 degrees + cos 3 degrees + ... + cos 357 + cos 358 degrees + cos 359 degrees.

Calculus
Find the exact values of the following. cos 270 degrees = 90 degrees, value = 0. Sin 180 degrees = 18090 = 90 = 1, but its supposed to be zero, don't know how to get that:\ Confused with tan 240 degrees as well.

pre calculus and trigonometry
already posted these questions but i could not find the post find all solutions from 0 degrees to 360 degrees 1. 4 sin^2x – 1 = 0 2. 2 sin^2x + sin x = 1 3. 2 sin^2x + 7 sin x = 4 4. cos x sin x + sin x = 0 5. 2 sin^2x  1 = 0

Physics (Calc Based)
I understand how to solve this problem ,however cannot figure out why the .5 degrees is being converted to radians: PROBLEM: How would one determine the percent uncertainty in theta and in sin of theta for the following: 1) theta = 15.0 degrees +/ 0.5

math
Determine the exact value of the following. a) sin300 degress b) tan (135 degrees) c)csc150 degrees d) sec45 degrees e) cos 4pi/3 f) sin (3pi/4)

trignometry
use degree measure for your answers. use a calculator and round the results to one decimal place for (c) and (d) (a) in triangle ABC, sin B = square root of 2 all over 2. What are the possible values for angle B? my thought: since sin is positive in the

Math/precal
Find the exact value of: (1sin^2 pi/2)/(cos^2 28 degrees + sin^2 28 degrees)

MATH
1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL STEPS) sin 2x  sin x = 0 2.) GIVEN: sin u = 3/5, 0 < u < ï/2 Find the exact values of: sin 2u, cos 2u and tan 2u using the doubleangle formulas. 3.)Use the halfangle formulas to

Trigonometry
use the appropriate trig identity (sum and difference, half angle, double angle) to find the exact value. 1)cos 255 degrees 2) sin 165 degrees 3) tan 285 degrees

Math Please Assist
Solve exactly for x: sin^3 x + sin x cos^2 x = cos x If 0 degrees

Math(Please check)
1) Use the cofunction identites to evaluate the expression without the aid of a calculator. cos^2 18 degrees + cos^2 72 degrees. Would I use the forumula cos(pi/2  Q) = sin Q

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 π/6 sin π/4 I get all those steps. The part I am

precal
Simplify the given expression........? (2sin2x)(cos6x) sin 2x and cos 6x can be expressed as a series of terms that involve sin x or cos x only, but the end result is not a simplification. sin 2x = 2 sinx cosx cos 6x = 32 cos^6 x 48 cos^4 x + 18 cos^2 x 

Maths
Find a if a is between 0 degrees and 180 degrees, and: a. Sin a = cos a b. sin^2 = 3/4 c. tan^2 = 1/3 I have no clue on where to start any help would be much appreciated.

Pre Cal
sin theta  2sin^2 theta = 0 I'm using the up carrot sign to signal "to the power of..." Let sin theta = x x  2 x^2 = 0 x (1  2x) = 0 Both x=0 and x = 1/2 are solutions. theta = 0 degrees, 30 degrees, 150 degrees and 180 degrees. Thank you so much!!! im

Math
How do you express in terms of angles less than 90 degrees? sin 120 degrees cos 150 degrees tan 280 degrees

Trigonometry
Solve the equation cos^2A = sin^2A + sinA when 0¨¬¡A¡360¨¬. Select all the solutions from the list below. A. 330 degrees B. 270 degrees C. 150 degrees D. 30 degrees

Precal
I do not understand how to do this problem ((sin^3 A + cos^3 A)/(sin A + cos A) ) = 1  sin A cos A note that all the trig terms are closed right after there A's example sin A cos A = sin (A) cos (A) I wrote it out like this 0 =  sin^6 A  cos^6 A +

HELP! math........quick will only take like 2 min.
What two sides of a right triangle will give you the following? 34. sin 0

math
Prove that for all real values of a, b, t (theta): (a * cos t + b * sin t)^2

trig
it says to verify the following identity, working only on one side: cotx+tanx=cscx*secx Work the left side. cot x + tan x = cos x/sin x + sin x/cos x = (cos^2 x +sin^2x)/(sin x cos x) = 1/(sin x cos x) = 1/sin x * 1/cos x You're almost there. thanks so

math
Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the symmetry of the graphs of sin, cos and tan, to find the exact values of si pi/6, cos 5/3pi and tan 4pi/3. I have found the answers to the first three using the special tables

math
Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the symmetry of the graphs of sin, cos and tan, to find the exact values of sin pi/6, cos 5/3pi and tan 4pi/3. I have found the answers to the first three using the special tables sin pi/6

Mathematics  Trigonometric Identities  Reiny
Mathematics  Trigonometric Identities  Reiny, Friday, November 9, 2007 at 10:30pm (sinx  1 cos^2x) (sinx + 1  cos^2x) should have been (sinx  1 + cos^2x) (sinx + 1  cos^2x) and then the next line should be sin^2x + sinx  cos^2xsinx  sinx  1 +

math
There are no typos and no work b/c I don't know how to do them. Thanks. 1)Find cos theta if sin theta=3/5 and 90 degrees

Calculus repost
Does anybody know how to solve this question? a) Find the arc length function for the curve measured from the point P in the direction of increasing t from P and then reparametrize the curve with respect to arc length starting from P. b) Find the point 4

trig
find the exact solutions (è in degrees) sin^2è+2cosè=2 change the sin^2 to 1cos^2, then rearrage the equation into quadratic form, use the quadratic equaion.

Physics
An item is shot off the ground at a force of 31N and an angle of 36 degrees. In order to find the vertical force, would I use SIN, COSINE, or TANGENT? would it go 31 * COS/SIN/TAN (36) or 36 * COS/SIN/TAN (31)??

Trig
If tan a= 12/15, 0 degrees < a < 90 degrees, then find the exact value of each of the following: A. Sin a/2 B. Cos a/2 C. Tan a/2

Math Help
Hi! Can someone help check this for me and see if I'm doing it right? Thanks!! :) Directions: Use the HalfAngle formulas to determine the exact value of sin(pi/12). Here's what I have: π/12 = ( 180° ) / 12 = 15°. = sin ( π/12 ) = sin 15° = sin ( 45°

Quantum Physics
We have a qubit in the state ψ>= √3/2 0>+ 1/2 1>, which we want to measure in the {Cos θ 0> + Sin θ 1>, Sin θ 0>  Cos θ 1>} basis. In order for the two possible outcomes to be equiprobable, what should be the value of θ in degrees? (Answer

Physics
We have a qubit in the state ψ>= √3/2 0>+ 1/2 1>, which we want to measure in the {Cos θ 0> + Sin θ 1>, Sin θ 0>  Cos θ 1>} basis. In order for the two possible outcomes to be equiprobable, what should be the value of θ in degrees? (Answer

trigonometry
We begin by setting t=sin 18 degrees we weill think of t an an "unknown" angle and solve to get the exact value. Use a double angle formula to show that cos 36 degrees=12t^2

Climate Physics
Find the insolation in Wm^2 at summer solstice for a low obliquity of 22 degrees? I used the following: h_0=cos^1(tan(phi)* tan(delta)) cos(theta)=[sin(phi)*sin(delta)+cos(phi)*cos(delta)*cos(h_0)] Result was 397 Wm^2 This looked like an easy problem,

math
Eliminate the parameter (What does that mean?) and write a rectangular equation for (could it be [t^2 + 3][2t]?) x= t^2 + 3 y = 2t Without a calculator (how can I do that?), determine the exact value of each expression. cos(Sin^1 1/2) Sin^1 (sin 7pi/6)

PRE CALC
1. solve tan36 degrees tan2degrees/ 1+tan36 degrees tan 2 degrees as a single function. 2. Find the exact value of sin (αβ) if sina=4/5 and cos β= 9/41 terminal side of α lies in I and terminal side of β lies in III 3. If cosx=1/12 and sinx > 0,

maths
can some one help me here : if 5 cos x + 3 = 0 and 180 degrees < x < 306 degrees , find the value of 3 tan x + 25 sin^2 x

Math
In obtuse triangle PQR, P=51 degrees, p= 10cm, and the longest side, q=12cm.Draw the triangle and solve for Q to the nearest degree. I did, 10/sin 51=12/sin Q 10(sin Q)/10=12(sin 51)/10 Q= 2nd function sin 0.9325751 Q=68 degrees Q=18068 Q=111 degrees

HELPPPPPPP (TRIG)
find, to the nearest minute, the solution set of 1 sin x = 3 cos^2 x over the domain 0 degrees to 360 degrees

AP Calculus
Find the velocity, v(t), for an object moving along the xaxis if the acceleration, a(t), is a(t) = cos(t)  sin(t) and v(0) = 3 v(t) = sin(t) + cos(t) + 3 v(t) = sin(t) + cos(t) + 2 v(t) = sin(t)  cos(t) + 3 v(t) = sin(t)  cos(t) + 4

Calculus
Find the velocity, v(t), for an object moving along the xaxis if the acceleration, a(t), is a(t) = cos(t) − sin(t) and v(0) = 3. a) v(t) = sin(t) + cos(t) +3 b) v(t) = sin(t) + cos(t) +2 c) v(t) = sin(t)  cos(t) +3 d) v(t) = sin(t)  cos(t) +4

math
how to define arc cosine(cosine x) for 360 deg

maths
Choose three options which are true: a) an angle of 150 degrees is equivalent to 2pie/3 radians. b) Cos 0 = cos (0 – pie/2) for al values of 0. c) Sin 0 = cos (0 – pie/2) for all values of 0. d) If triangle ABC has a right angle at B, then sin A = cos

trig 30
If cos^2 theta 6 sin 2 theta =0, one value of theta is a)0 degrees b) 90 degrees c)180 degrees or D)255 degrees. Please show me how to do it and not just give answer cause I have two more questions that are similar. Thanks so much.

Pre Calculus
I have tried and tried to understand double angle identities but it just won't stick. if sin x = 0.6 and 180 (degrees) < x < 270 (degrees), find the exact value of sin 2x

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 value of sin(sin^1(20