# If sinA=3/5 when pi/2 < A < pi and cosB=5/13 when 3pi/2 < B < 2pi, find the exact value of the function cos(5pi/6+B)

1,475 results
1. ## Calculus

Find all points of extrema on the interval [0, 2pi] if y=x+sinx (-1.-1+(3pi/2)) (pi, pi) (-1,0) ((3pi/2), 0) none of these I got pi as my critical number but I'm confused with the intervals.

2. ## Algebra 2

Find the values of the inverse function in radians. sin^-1(0.65) a. 0.71+2pi n and -0.71+2pi n b. 0.71+2pi n and -3.85+2pi n c. 0.86+2pi n and -0.86 +2pi n d. -0.61+2pi n and 2.54+2pi n 2. tan^-1(0.09) a.-0.09+2pi n b. no such angle exists c.-1.48+ pi n d.

3. ## Algebra 2

What values for theta(0

4. ## Math

If A and B are acute angle such that SinA=8/17 and CosB=3/5.Find 1, Cos(A+B) 2, Sin(A+B) 3, Sin(A-B)

5. ## Math

if sinA+sinB=x and cosA-cosB=y then find tan[(A-B)/2]

6. ## Pre-Calculus

If sinA=3/5 when pi/2 < A < pi and cosB=5/13 when 3pi/2 < B < 2pi, find the exact value of the function cos(5pi/6+B).

7. ## Trigonometry

If sinA + sinB = a and cosA + cosB = b, find the value of tanA-B/2

8. ## Precalculus

Solve for x given the interval of [0,2pi). cos^2x=2+2sinx I got (3pi)/2 or 270 degrees.. By the way, does the notation [0,2pi) mean 0

9. ## APCalculus

For the function y=2sin(x)-cos^2(x) on [0, 2pi] find the following: Domain x and y intercepts Vertical asymptotes Horizontal asymptotes Symmetry F'(x) Critical numbers Increasing f(x) Decreasing f(x) Extrema F"(x) Possible points of inflection Concave up

10. ## Trigonometry

Prove that 1-cosA+cosB-cos(A+B)/1+cosA-cosB-cos(A+B) = tanA/2cotA/2

11. ## math

If A + B + c = 180 then show that sinA + sinB + sinC=4cosA/2. cosB/2 . cosC/2

Determine the value of Tan2x when Sinx = -12/13 and 3pi/2 < x < 2pi.

13. ## Math

If 1/sinA+1/cosA =1/sinB+1/cosB, prove that: cot(A/2+B/2) = TanA. TanB

14. ## trig

prove 1-cosB divided by 1+cosB= tan^2B/2

15. ## math

if cos(B-C)+cos(C-A)+cos(A-B)=-3/2 then prove that cosA+cosB+cosC=O and sinA+sinB+sinC=O after that prove that cos(B-C)=cos(C-A)=cos(A-B)=-1/2

16. ## Pre-Calc/Math

Given cos x=2/3 and 3pi/2

17. ## Trigonometry

If sinA=3/5 and cosB=5/13 and if A and B are measures of two angles in Quadrant I, find the exact value of the following functions. cotB = sin2A= 3)cos(5pi/6 + B) = tan(A - pi/4) =

18. ## precalculus

Find the tan(x), the sin (x + pi) if it is known that cos (x)=.6 and that (3pi)/2 less than x less than 2pi. Find the sine (2x), the tan (2x), and the cos (x/2) if it is known that cos (x)=.6 and that (3pi)/2 less than x less than 2pi.

19. ## Pre-calculus (Trigonometry)

The rotating spotlight from the Coast Guard ship can illuminate up to a distance of 250 m. An observer on the shore is 500 m from the ship. HIs line of sight to the ship makes an angle of 20 degrees with the shoreline. What length of shoreline is

20. ## Trigonometry

IfA=340°, prove that 2sinA/2 = -(v1+sinA) + (v1-sinA)

21. ## Pre-Calculus

Hello, I need a bit of help with the following problem: If sinA=3/5 when pi/2 < A < pi and cosB=5/13 when 3pi/2 < B < 2pi, find the exact value of the following equations: cotB = sin2A = tan(A-pi/4)=

State the period and phase shift of the function y=-4tan(1/2x + 3pi/8) a) 2pi, -3pi/4 b) pi, 3pi/8 c) 2pi, 3pi/8 d) pi, -3pi/8 Answer: d 2) What is the equation for the inverse of y=cos x+3: a) y=Arccos(x+3) b) y=Arccos x-3 c) y=Arccos x+3 d) y=Arccos(x-3)

23. ## Calculus

Determine whether the curve has a tangent at the indicated point. f(x)= sin x 0

24. ## Trig

Find all solutions of the equation in the interval [0,2pi) 2 cos^2 x-cos x = 0 -2cos^2 + cosx + 0 (x+1/2) (x+0/2) (2x+1) (x+0) -1/2,0 2Pi/3, 4pi/3, pi/2, 3pi/2 my teacher circled pi/2 and 3pi/2 What did I do wrong? I don't understand...

25. ## precalculus

Given sina= 3/4 and cosB = (-5)/13 and this is Quad II find cos(a+B)

26. ## trig

Solve the equation for cos theta-tan theta=0 for greater than or egual to zero but less than 2pi. Write your answer as a multiple of pi, if possible form the following choices: pi , 5pi A. --- ---- 4___ 4 B. pi 3pi 5pi 7pi ----- '----- '-----'----- 4_____

27. ## math

12. IF 1/SinA+1/CosA=1/SinB+1/CosB ,PROVE THAT: Cot{(A+B)/2}=TanA.TanB

28. ## Trigonometry

4. Write the equation of the cosine function with an amplitude of 1/3, a period of 2pi, and a phase shift of 3pi/2. I got 1/3COS(1/2x-3pi), but I really do not think that is correct D: any tips or advice?

29. ## Trig - check my answers plz!

1. (P -15/17, -8/17) is found on the unit circle. Find sinΘ and cosΘ Work: P= (-15/17, -8/17) cosΘ = a value P = (a,b) sinΘ = b value Answer: cosΘ = -15/17 sinΘ = -8/17 2. Should the triangle be solved beginning with Law of Sines or Law of Cosines.

30. ## Trig

Please help with this one. I've worked it out in so many ways and can't tell what's correct. sinA sinA ----- - ------ 1+sinA 1-sinA Which answer is correct for the problem above? a) 1+cotA b) sinA tanA c) -2tan^2A d) secA cscA common denominator: 1-sin^2 A

31. ## Maths

(1) Find the value of B between 0 degree and 360 degree which satisfy the equation SinB+Sin²B=0 (2) Find the value of A between 0 degree and 360 degree which satisfy the equation (2CosA+1)(1-CosA)=0 (3) 2Sin²A-SinA-1=0 (4) 4Cos²A+2CosA=1 (5)

32. ## Trigonometry

Graph the function y=2sin(x-2pi/3). To draw the graph, plot all x-intercepts, minima and maxima within on period. I need to graph at least 5 points. I have -pi, 0, pi, 2pi, 3pi, and 4pi along the x-axis

33. ## trig

Find another angle theta between 0 and 2pi that has the same cosine as 3pi/14

34. ## Math

Find the solutions of sin5x + sin3x = 0 in the interval 0, 2pi. My answer: 0, pi/2, pi, 3pi/2

35. ## Maths

Prove that [sinA/(1-cosA)-(1-cosA)/sinA]*[cosA/(1+sinA)+(1+sinA)/cosA]=4cosecA I the second part as 2 secA

36. ## trig

if 5cos A plus 3=0 and 180

37. ## Maths

Cos^2A/sinA-cosecA+sinA=0 Prove lHS =RHS

38. ## trig

Solve cos x-1 = sin^2 x Find all solutions on the interval [0,2pi) a. x=pi, x=pi/2, x= 2pi/3 b. x=3pi/7, x=pi/2, x=2pi/3 c. x=3pi/7, x=3pi/2, x=3pi/2 d. x=pi, x=pi/2, x=3pi/2

39. ## math

find all solutions in the interval [0,2 pi) sin(x+(3.14/3) + sin(x- 3.14/3) =1 sin^4 x cos^2 x Since sin (a+b) = sina cosb + cosb sina and sin (a-b) = sina cosb - cosb sina, the first problem can be written 2 sin x cos (pi/3)= sin x The solution to sin x =

40. ## further mathematics

Let P=(cosA sinA) (sinA cosA) Q=(cosB sinA) (sinB cosA) show that PQ=(cosA(A-B) sin(A B)) (sinA(A B) cos(A-B))

41. ## calculus

given the graph of f(x) = x sinx, 0

42. ## Math

If the function is: f(x)=2cos(x)-1 [0,2pi] A) What are the intervalos of concacity? B) What are the inflection pinta My answers: A) concave down: [0,pi/2) and (3pi/2, 2pi] concave up: (pi/2, 3pi/2) B) inflection points: (pi/2, -1) (3pi/2, -1) Please check

43. ## CALC HW

FIND THE X VALUES OF ALL POINTS, -2PI LESS THAN OR EQUAL TO X LESS THAN OR EQUAL TO 2PI, WHERE Y=X+B IS TANGENT TO Y=X+BSINX. I KNOW THE ANSWER IS PI/2 AND 3PI/2, BUT WHY AREN'T THEY PLUS OR MINUS. If they are tangent, they have the same coordinates, and

Approximate the equation's solutions in the interval (0,2pi) sin2x sinx = cosx 2cos(x) (1/2-sin^2x) = 0 Then I got 3pi/2, pi/2, pi/6 and 5pi/6 Then I substituted 0-3 and got 3pi/2 , 5pi/2 , 9pi/2 , pi/2, pi/6, 7pi/6, 13pi/6 , 19pi/6 , 5pi/6 , 11pi/6 ,

45. ## precal desperate

Given sina= 3/4 and cosB = (-5)/13 and this is Quad II find cos(a+B)

46. ## maths

Please can you help me with this question? Choose the option which is a false statement: A arctan(tan2/3pi))=-1/3pi B arccos(cos(3/4pi))=3/4pi C sin(arcsin(-1/2pi))=-1/2pi D arcsin(1/2squareroot3)=1/3pi E arcsin(sin(3/4pi))=1/4pi F arccos

47. ## Math

If sinA+sinB=1/2 and cosA+cosB=1/2 then the value of tanA+tanB

48. ## mathematics

if sinA+sinB=x and cosA-cosB=y then find tan[(A-B)/2]

49. ## Math III

What values for theta(0

50. ## math

Given that [sin(A-B)/cos(A+B)]=1/3[tan(A-B)], find the values of cosB if sinA=1/2

51. ## trig

if tan x= 4/3 and pip < x < 3pi/2, and cot y= -5/12 with 3pi/2 < y < 2pi find sin(x-y)

53. ## pre cal

cosA (-7/25) pi < A < 3pi/2 sin B= -3/5 3pi/2

54. ## Precalculus

Solve for x given the interval of [0,2pi). cos^2x=2+2sinx I got (3pi)/2 or 270 degrees.. By the way, does the notation [0,2pi) mean 0

55. ## Math:)

A weight is attached to a spring that is oscillating up and down. it takes 3 sec. for the spring to complete one cycle, and the distance from the highest to lowest point is 4 in. What equation models the position of the weight at time t seconds? a.

56. ## calculus

given the graph of f(x) = x sinx, 0

given the graph of f(x) = x sinx, 0

58. ## Math

Can I please get some help on these questions: 1. How many solutions does the equation,2sin^2 2 θ = sin2θ have on the interval [0, 2pi]? 4? ...what about 4cos2θ = 8cos^2 2θ? 2. True or False: sin^2 4x = 1 has 8 solutions on the interval [0, 2pi]?

59. ## Maths

Hi, can someone give me the answer to this question: secA-tanA=1/4. Find cosA I got: CosA=4(1-sinA) Is my answer good? Now multply each side by (1+sinA) CosA(1+sinA)=4 cos^2 A CosA=1/4 (1+sinA) 16(1-sinA)=1+sinA 15=17SinA So you have sinA, now find Cos A

60. ## Math

If A and B are acute angle such that SinA=8/17 and CosB=3/5.Find 1, Cos(A+B) 2, Sin(A+B) 3, Sin(A-B)

61. ## Trigonometry.

Use the given information to evaluate cos (a-b). Cot a = 3/4, cot b = 24/25; pi

62. ## Calculus

1) The period of a trig. function y=sin kx is 2pi/k. Then period of y=sin^2(pi.x/a) should be 2pi/(pi/a)=2a, but somewhere it is given as a. Which is correct? 2) The period of r=sin^3(theta/3) is given as 3pi. How is it worked out? Is it because after

1) Find the Asymptotes: y = -2 sec 2pi x pi/2b and 3pi/2b pi/2(2pi) = pi/4 and 3pi/4 Is this correct? 2) Find the period and asymptotes: y = 1/2 sec pi x / 2 b = pi/2 I do not know how to find the period of asymptotes for this one. My original answer was 1

64. ## ordinary differential equation

a periodic function f(t) is defined by f(t) = t+pi -pi

65. ## calculus

Given the function y = 2cos(x) - 1, use Calculus methods to determine the: a) intervals of increase and decrease b) local max and mins c) intervals of concavity d) inflection points my answers: a) decrease: [0,pi) increase: (pi,2pi] b) local min: (pi,-3)

66. ## Algebra2

Find the values of the inverse function in radians. 1. sin^-1(0.65)? answer choices: a. 0.71+2pi n and -0.71+2pi n b. 0.71+2pi n and -3.85+2pi n c. 0.86+2pi n and -0.86 +2pi n d. -0.61+2pi n and 2.54+2pi n My answer is B

67. ## Math

CosA+cosB-cosC=4COSA/2 cosB/2 SINC/2-1

68. ## Math

Hello I am having trouble with proving this: sinA/secA+secA/cscA = tan(A)(2-sin^2(A)) So far I've gotten SinA/(1/cosA) + (1/cosA)/(1/sinA) SinACosA + sinA/cosA I am stuck here, not even sure if multiplying by the reciprocal was the right step..

69. ## Trigonometry

I really need help with this trigonometry question.please any help is appreciated. 1.I have to draw the graph of y=cos x from 0deg to 360deg. 2.Be sure to show a table of vales similar to the this table. colum X l colum :y=sinx 0 l 0.00 pi/10 l 0.31 pi/5 l

70. ## pre-calc

Can someone help me find the exact value of 4csc(3pi/4)-cot(-pi/4)? Thanks! cotx =1/tanx cscx = 1/sinx If you find it easier to conceptualize in degrees, realize that pi/4 radians is 45º and 3pi/4 is then 135º If you know the CAST rule, it is easy to see

71. ## Pre calc

Evaluate the expression given that cosine a=4/5 with 0

72. ## Math

For questions 2 and 3, use a calculator to find the values of the inverse function in radians. sin^-1(0.65) 0.71 + 2pi n and –0.71 + 2 pi n 0.71 + 2 pi n and –3.85 + 2 pi n 0.86 + 2pi n and –0.86 + 2pi n –0.61 + 2pi n and 2.54 + 2 pi n

73. ## Math

Match each ratio in the first row with an equivalent ratio from the second row if angle A plus angle B = 90 degrees. SinA CosA TanA CscA SecA CotA SinB CosB TanB CscB SecB CotB Pleaseeee help!!

74. ## Math

In any angle ABC prove that the perimeter = a/Sin A(Sin A + Sin B + Sin C) Start with perimeter = a+b+c but b= aSinB/sinA and c= aSinC/SinA and if you don't remember, a=a=a*SinA/ SinA

75. ## trig

Match each ratio in the first row with an equivalent ratio from the second row if angle A plus angle B = 90 degrees. SinA CosA TanA CscA SecA CotA SinB CosB TanB CscB SecB CotB Does this question even make sense?

76. ## Math

The circumference of a circle, divided by its radius equals A. pi/2 B. pi C. 3pi/2 D. 2pi I got D, is that correct?

77. ## Math-precalc

Compute or solve the following in radians without a calculator a. csc x=2, pi/2 ≤ x ≤ pi b. cot x= -1 , 3pi/2 ≤ x ≤ 2pi Thanks!

78. ## Math

In the interval 0

Find the surface area and volume of each of the following figures: d.Right circular cylinder v=pir^2h pi(3)(3)(6) pi(54) v=169.6 cubic cm sa=2pi r^2 + 2pi rh 2pi(3)(3)+2pi(3)(6) 2pi(9)+2pi(18) 56+113=169 Sa=169 square cm is this right???

80. ## Calculus help??

I'm not sure how to solve this and help would be great! d/dx [definite integral from 0 to x of (2pi*u) du] is: a. 0 b. 1/2pi sin x c. sin(2pi x) d. cos (2pi x) e. 2pi cos (2pi x) This is the fundamental theorem, right? What's confusing me is the u and du

81. ## Trig

How do I find all solutions in the interval [0, 2Pi): cotx=cscx-1 the answer choices are: a.) x=Pi/2 b.) x=Pi/2 and 3Pi/2

82. ## Trig

Use a half-angle identity to find the exact value for sec(x/2) if sinx = -12/13 ; 3pi/2 < x < 2pi

83. ## Math

Test for symmetry with repsect to Q=pi/2, the polar axis, and the pole. r=16cos 3Q r=16cos(3pi/3 + 3h) = 16(cos3pi/2 3h- sin 3pi/2 sin h) cos 3pi/2 = 0 sin 3pi/2 = -1 Not symmetrical My teacher said that this was wrong!Why?

84. ## Math

Test for symmetry with repsect to Q=pi/2, the polar axis, and the pole. r=16cos 3Q r=16cos(3pi/3 + 3h) = 16(cos3pi/2 3h- sin 3pi/2 sin h) cos 3pi/2 = 0 sin 3pi/2 = -1 Not symmetrical My teacher said that this was wrong!Why?

85. ## Trigonometric Identities

Verify/prove the following: (sinA+tanA)/(1+secA) = sinA ______________________________ tanu = 1+sinu-cos^2u/cosu(1+sinu) __________________________________ cotu = (2+cscu/secu)-2cosu ______________________________ tanAsinA/tanA+sinA = tanA-sinA/tanAsinA

86. ## trig

If S is an element of [ 3pi/2 , 2pi ] what quadrant does the terminating side lie in and evaluate for sine theta

87. ## math

1)Find the amplitude of y=6cos4theta A)3/2 B)6 C)4 D)pi/2 I chose B 2)Find the period of y=tan5theta A)10pi B)2pi/5 C)5pi D)pi/5 I chose D 3)Find the phase shift of y=sin(theta-3pi/4). A)3pi/4 B)-3pi/4 C)4pi/3 D)-4pi/3 I chose A 4)Find the vertical shift

88. ## Maths

Prove that CosB-cosA/cosA+cosB=tanA+B/2tanA-B/2

89. ## 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 t.

90. ## math

Hello there, im doing an equation and its mind boggling me badly so i want to see if im doing something wrong or not. It goes like this: sinx - Squareroot of 3/2 > 0 x € [0,2pi) i start by moving the sqroot of 3.. so i have sinx >sq3/2. as of that my

91. ## algebra

i need someone to explain to me how i got this answer...i know the answer but i need an explanation to the problem... C=2pi(r) the answer is r=C/2pi...i need someone to explain it to me..thank you C = 2pi(r) Divide both sides by 2pi C/2pi = r ----> r =

92. ## Pre-calculus

Find in terms of a & pi, the sum of the first 50 terms of the series: a+pi, a^2+2pi, a^3+3pi...where a is a fixed real number.

93. ## math

Find in terms of a & pi, the sum of the first 50 terms of the series: a+pi, a^2+2pi, a^3+3pi..where a is a fixed real number.

94. ## Trig

can you please simplify these in faction form? (pi/3) +1=? (2pi/3) +1=? (3pi/4) +1=? (5pi/4) +1=? (5pi/3) +1=? thank you so much!

95. ## Trig - Ambiguous Cases

Triangle HAV has

96. ## Math

What is the exact answer to cos^2x - sin^2x = 0 for between 0 and 2pi? I got x = pi/4 and x = 5pi/4. But the answer key says there are two additional answers which are 3pi/4 and 7pi/4. I don't know how to get these. Any help is much appreciated!

97. ## calculus

For large values of n, the Riemann sum 1/n(sin0 + (pi/2n) + sin(2pi/2n) +sin(3pi/2n)+...sin((n-1)pi/2n)) is an approximation for which of the following integrals?

98. ## precalculus

Solve sin theta=-1 for all real values of theta. Is it theta=3pi/2 +2pi n for n=0+ infinity?

99. ## math

Solve each equation for 0

100. ## Trig

IfA=340°, prove that 2cosA/2 = -(v1+sinA) - (v1-sinA)