# ((2X-14Cos45)/(49+X^2-14XCos45))+0.3536 = 0 Solve to find the value of X Change cos 45 to sqrt 2 and rewrite the equation in the form a x^2 + bx + c = 0 Start out by rewriting it as 2x - 9.8995

133,634 results
1. ## finding c: calc

let f(x)=square root x. if the rate of change of at x=c is twice its rate of change at x=1, then c=? what???? i don't get get it. to begin with, i took the derivative if that helps which is 1/(2*sqrtx) . f'(x) = 1/(2*sqrtx) is correct f'(x=1) = 1/2 The

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 r=sqrt -5^2+-4^2 r=sqrt 41

3. ## Precalculus check answers help!

1.) Find an expression equivalent to sec theta sin theta cot theta csc theta. tan theta csc theta sec theta ~ sin theta 2.) Find an expression equivalent to cos theta/sin theta . tan theta cot theta ~ sec theta csc theta 3.) Simplify (tan^2 theta +

4. ## Calculus

Find the rate of change of f(x,y,z) = xyz in the direction normal to the surface yx^2 + xy^2 + yz^2 = 75 at (1,5,3). I keep getting this wrong and I don't know what I did right. The answer's 147/sqrt(101) but I got 357/sqrt(1361). Is my method right? Or

5. ## calculus

Find complete length of curve r=a sin^3(theta/3). I have gone thus- (theta written as t) r^2= a^2 sin^6 t/3 and (dr/dt)^2=a^2 sin^4(t/3)cos^2(t/3) s=Int Sqrt[a^2 sin^6 t/3+a^2 sin^4(t/3)cos^2(t/3)]dt =a Int Sqrt[sin^4(t/3){(sin^2(t/3)+cos^2(t/3)}]dt=a Int

6. ## math;)

Find the unit vector in the direction of u=(-3,2). Write your answer as a linear combination of the standard unit vectors i and j. a. u=-3[sqrt(13)/13]i+2[sqrt(13)/13]j b. u=-3[sqrt(5)/5]i+2[sqrt(5)/5]j c. u=3[sqrt(5)/5]i-2[sqrt(5)/5]j d.

7. ## math

Solve for the indicated variable A=1/2 bh Solve for b 2A = bh, so b = 2A/h ok thanks so on this example C=2pie r Solve for R Would the answer be 2C/pie=r ???? ok thanks so on this example C=2pie r Solve for R Would the answer be 2C/pie=r ???? Divide both

8. ## Pre-calculus

solve 4 sin^2x + 4 sqrt 2 cos x-6=0 for all real values of x. Going by the example in the book I got to: 4 cos^2x + 4sqrt2 cosx -10 = 0 but do not know how to proceed. Any help would be great. Thanks

9. ## math;)

The equation 2sinx+sqrt(3)cotx=sinx is partially solved below. 2sinx+sqrt(3)cotx=sinx sinx(2sinx+sqrt(3)cotx)=sinx(sinx) 2sin^2x+sqrt(3)cosx=sin^2x sin^2x+sqrt(3)cosx=0 Which of the following steps could be included in the completed solution? a.

10. ## Trig(3 all with work)

1)Find the exact value of cos 105 by using a half-angle 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

11. ## Trig

Find the exact value of sin2(theta) if cos(theta) = -sqrt 5/3 and 180 < theta < 270. A)-1/9 B)-4 sqrt 5/9 C)1/9 D)4 sqrt 5/9 B? sin^2(theta) + cos^2(theta) = 1 sin^2(theta) = 1 - cos^2(theta) sin^2(theta) = 1 - (sqrt 5/3)^2 sin^2(theta) = 1 - (sqrt 25/9)

12. ## algebra

simplify: square root of 5 + square root of 20 - square root of 27 + square root of 147. simplify: 6/4square root of 2 sqrt 5 + sqrt 20 - sqrt 27 + sqrt 147 = sqrt 5 + sqrt (4*5) - sqrt (3*9) + sqrt (49*3) = 3 sqrt 5 - 3 sqrt 3 + 7 sqrt 3 = 3 sqrt 5 + 4

13. ## Algebra

Evaluate sqrt7x (sqrt x-7 sqrt7) Show your work. sqrt(7)*sqrt(x)-sqrt(7)*7*sqrt(7) sqrt(7*x)-7*sqrt(7*7) sqrt(7x)-7*sqrt(7^2) x*sqrt 7x-49*x ^^^ would this be my final answer?

14. ## Vectors/Tension

A horizontal clothesline is tied between 2 poles, 20 meters apart. When a mass of 5 kilograms is tied to the middle of the clothesline, it sags a distance of 2 meters. What is the magnitude of the tension on the ends of the clothesline? Alright, so i have

15. ## calculus

Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x ln y = x ln(cos x) (dy/dx)/(y)= ln(cos x) (dy/dx)= y ln(cos x) = (cos x)^x * (ln cos x) (dx/du)= x(cos x)^(x-1) * (-sin x) = - x sin(x)cos^(x-1)(x) (dy/dx)-(dx/du)=

16. ## math

solve 2x^2+3x+8=0 and express the solutions in a+bi form. Let's use the quadratic formula to solve for x and express those solutions in a+bi form. x = [-b + or - sqrt(b^2 - 4ac)]/2a Note: sqrt = square root. a = 2, b = 3, and c = 8 from your problem.

1. Find the modulus and argument of the following complex numbers, and write them in trigonometric form: a. 5 – 8i Answer = Sqrt{89} ( cos (-1.01219701) + i sin ( -1.01219701)) b. –1 – i answer = Sqrt2 (cos (5pi/4) + i sin (5pi/4)) c. –5 + 12i

18. ## Calculus - Second Order Differential Equations

Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i, alpha=8, Beta=Sqrt(2) y(0)=2, e^(8*0)*(c1*cos(0)+c2*sin(0))=c2=2 y'(0)=4, c2=4

19. ## calc check: average value

Find the average value of the function "f(x) = x^2 sqrt(1+x^3)" on the interval [0,2]. and this is what i did.. please check for mistakes. thanks :D f(x) = x^2 sqrt(1+x^3), [0,2] f ave = (1/(b-a))*inegral of a to b for: f(x) dx f ave = (1/(2-0))*integral

20. ## Inequality

When I solve the inquality 2x^2 - 6 < 0, I get x < + or - sqrt(3) So how do I write the solution? Is it (+sqrt(3),-sqrt(3)) or (-infinity, sqrt(3))? Why? Thanks. So would this work? abs x < ( sqrt 3 ) or - sqrt 3

21. ## calc: avg value

Find the average value of the function "f(x) = x^2 sqrt(1+x^3)" on the interval [0,2]. and this is what i did.. please check for mistakes. thanks :D f(x) = x^2 sqrt(1+x^3), [0,2] f ave = (1/(b-a))*inegral of a to b for: f(x) dx f ave = (1/(2-0))*integral

22. ## Algebra 2

Operations with Complex Numbers Simplify. 1. sqrt(-144) 2. sqrt(-64x^4) 3. sqrt(-13)*sqrt(-26) 4. (-2i)(-6i)(4i) 5. i13 6. i38 7. (5 – 2i) + (4 + 4i) 8. (3 – 4i) – (1 – 4i) 9. (3 + 4i)(3 – 4i) 10. (6 – 2i)(1 + i) 11. (4i)/(3+i) 12. (10+i)/(4-i)

23. ## Trig Practice

Find the exact value of sinA where a=9 and b=10 and angle C is a right angle. a. sin A= 9/sqrt 181, cos A= sqrt 181/10 b. sin A= sqrt 181/9, cos A= 10/sqrt 181 c. sin A= 9/sqrt 181, cos A= 10/sqrt 181 d. sin A=sqrt181/10, cos A= 9/sqrt 181

24. ## math!!

I have no idea how to do this!!! Let ΔABC be a triangle such that b=sqrt(3), c=sqrt(10), and cos(B)=3/sqrt(10). Find all possible values for side length a. Please show work

1) Evaluate (if possible) the sine, cosine, and tangent of the angles without a calculator. a) 10pi/3 Sin = -sqrt 3/2 Cos = -1/2 Tan = sqrt 3 Are these correct ? I do not understand when to make them negative. b) 17pi/3 Sin = -sqrt 3/2 Cos = 1/2 Tan = -

26. ## Math:)

A person is on the outer edge of a carousel with a radius of 20 feet that is rotating counterclockwise around a point that is centered at the origin. What is the exact value of the position of the rider after the carousel rotates 5pi/12 radians? a.

27. ## 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

28. ## Math

If a and B are two angles in Quadrant 2 such that tan a=-1/2 and tan B= -2/3, find cos(a+b)? tan(a) = -1/2 oppsite side = 1: adjacentside = 2 hypotenuse = sqrt(1+4) = sqrt(5) sin(a) = 1/ã5 cos(a) = -2/ã5 tan(b) = -2/3 opposite side = 2 and

29. ## Math(Roots)

sqrt(24) *I don't really get this stuff.Can somebody please help me? The square root of 24 is 4.898979485566356 I know that..lol,but it says not to use decimals.Here is an example they gave me. Ex.sqrt(18)=sqrt(2*3*3)=3sqrt(2) sqrt[24] = sqrt[4*2*3] =

30. ## Solving for x

((2X-14Cos45)/(49+X^2-14XCos45))+0.3536 = 0 Solve to find the value of X Change cos 45 to sqrt 2 and rewrite the equation in the form a x^2 + bx + c = 0 Start out by rewriting it as 2x - 9.8995 = (-0.3536)(49 + x^2 - 9.8995 x) Conimue until you get the

31. ## URGENT - Trigonometry - Identities and Proofs

Okay, today, I find myself utterly dumbfounded by these three questions - Write a proof for - 2/(sqrt(3)cos(x) + sin(x))= sec((pi/6)-x) Solve the following equation - 2sin(2x) - 2sin(x) + 2(sqrt(3)cos(x)) - sqrt(3) = 0 Find all solutions (exact) to the

32. ## Precalculs

I have no idea how to do these type of problems. -------Problem-------- Solve each equation on the interval 0 less than or equal to theta less than 2 pi 42. SQRT(3) sin theta + cos theta = 1 ---------------------- There is an example prior to the

33. ## Calc.

Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x ln y = x ln(cos x) (dy/dx)/(y)= ln(cos x) (dy/dx)= y ln(cos x) = (cos x)^x * (ln cos x) (dx/du)= x(cos x)^(x-1) * (-sin x) = - x sin(x)cos^(x-1)(x) (dy/dx)-(dx/du)=

34. ## Precalculus check answers help!

1. Which expression is equivalent to cos 2theta for all values of theta ? cos^2 theta – sin^2 theta ~ cos^2 theta – 1 1 – 2 sin^2 theta 2 sin theta cos theta 2. Use a half–angle identity to find the exact value of sin 105°. -1/2(sqrt)(2 + Sqrt3)

35. ## CALC

1. The problem statement, all variables and given/known data cos(x) = -2 I was trying to solve that problem ignoring what people say about it not being defined and got a number strangely. I showed step by step so you can tell me what I did wrong as I don't

36. ## Math

So I am supposed to solve this without using a calculator: Sqrt[20]/10 - Sqrt[10]/Sqrt[32] - Sqrt[0.3125] + Sqrt[3 + 1/5] You can put this into WolframAlpha as is to make it prettier. Answer given is 1/2 * SQRT(5) I really don't know where to start here. I

37. ## Math - Solving Trig Equations

What am I doing wrong? Equation: sin2x = 2cos2x Answers: 90 and 270 .... My Work: 2sin(x)cos(x) = 2cos(2x) sin(x) cos(x) = cos(2x) sin(x) cos(x) = 2cos^2(x) - 1 cos(x) (+/-)\sqrt{1 - cos^2(x)} = 2cos^2(x) - 1 cos^2(x)(1 - cos^2(x)) = 4cos^4(x) - 4cos^2(x)

38. ## 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

39. ## PreCalculus

The question is: -5e^(-4x+2) +3= 1/2log(1+x^2) Solve with a calculator for the smallest possible solution, with steps. So this hasn't really been covered in my schoolwork so I'm trying to work off what I have learned. I started with the change of base

40. ## math- Trigonometry

If cos degree equals to 0.8641 What is Sin degree? I have no idea how to find this. Please help me. I got help from two people, but I'm not getting the answer and how they got the numbers either. Someone says: cos^2+sin^2=1 sinDegree=sqrt(1-cos^2degree)

41. ## Calculus

Please look at my work below: Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i, alpha=8, Beta=Sqrt(2) y(0)=2, e^(8*0)*(c1*cos(0)+c2*sin(0))=c2=2

42. ## Calculus - Second Order Differential Equations

Posted by COFFEE on Monday, July 9, 2007 at 9:10pm. download mp3 free instrumental remix Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i,

43. ## Math/Calculus

Solve the initial-value problem. Am I using the wrong value for beta here, 2sqrt(2) or am I making a mistake somewhere else? Thanks. y''+4y'+6y=0, y(0)=2, y'(0)=4 r^2+4r+6=0, r=(-4 +/- sqrt(16-4(1)(6))/2 r=-2 +/- sqrt(2)*i , alpha = -2, beta = 2(sqrt(2))

44. ## Trig/Precalc

So I have two questions that have been puzzling me for quite some time and would really appreciate any help with either of them! (a) There are four positive intergers a, b, c, and d such that 4cos(x)cos(2x)cos(4x)=cos(ax)+cos(bx)+cos(cx)+cos(dx) for all

45. ## Vectors

The angle between the vectors a=(6,-2,3) and b=(1,p,-2) is cos^-1(-1/14). Determine the value of p. |a|=sqrt(6^2+(-2)^2+3^2)=7 |b|=sqrt(1^2+p^2+(-2)^2)=5+p^2 theta=cos(cos^-1(-1/14))=-1/14 a x b = (4-3p,15,6p+2) a x b = |a||b|cos(theta) a x b = -sqrt(5/2)

46. ## math

A trigonmetric polynomial of order n is t(x) = c0 + c1 * cos x + c2 * cos 2x + ... + cn * cos nx + d1 * sin x + d2 * sin 2x + ... + dn * sin nx The output vector space of such a function has the vector basis: { 1, cos x, cos 2x, ..., cos nx, sin x, sin 2x,

47. ## calc

find the area between the x-axis and the graph of the given function over the given interval: y = sqrt(9-x^2) over [-3,3] you need to do integration from -3 to 3. First you find the anti-derivative when you find the anti-derivative you plug in -3 to the

48. ## Calculus AP

hi again im really need help TextBook: James Stewart:Essential Calculus, page 311. Here the problem #27: First make a substitution and then use integration by parts to evaluate the integral. Integral from sqrt(pi/2) TO sqrt(pi)of θ^3 cos(θ^2)dθ. i did

49. ## Calculus

In these complex exponential problems, solve for x: 1)e^(i*pi) + 2e^(i*pi/4)=? 2)3+3=3i*sqrt(3)=xe^(i*pi/3) MY attempt: I'm not really sure of what they are asking. For the 1st one I used the e^ix=cos(x)+i*sin(x) and got -1+sqrt(2) +sqrt(2)i 2) I solved

51. ## inverse

find f^-1 (x). (this is asking me to find the inverse) f(x) = -(x-2)^2, x If f(x)=-(x-2)^2 x

52. ## maths

Choose the option that gives the solution of the initial-value problem dy dx=(1 + 2 cos2x^2)/y (y > 0), y= 1 when x = 0. Options A y = 1+ 2sin^2 x B y = (1 + 2 sin x)^2 C y = (4x + cos(2x))^2 D y = 4x + cos^2 x E y =sqrt(4x + cos(2x) F y =sqrt(1 + 4x +

Could someone show me how to solve these problems step by step.... I am confused on how to fully break this down to simpliest terms sqrt 3 * sqrt 15= sqrt 6 * sqrt 8 = sqrt 20 * sqrt 5 = since both terms are sqrt , you can combine them. sqrt 3* sqrt 15=

54. ## Algebra

Solve for s: h=(square root of 3)times s/2 and solve for h V= (pi)r squared h / 3 Solve for s: h=(square root of 3)times s/2 Multiply both sides by 2. 2h = (sqrt 3)*s*2/2 which cancels the 2 on the right. 2h = (sqrt 3)*s Now divide the right side by

55. ## some algebra help (radicals)

I hope I am writing this down right.. I am trying to do some practice questions to learn 10^5 (sqrt)2y - 4^5 (sqrt)2y I am trying to figure out how to solve this They gave us some answers to choose from, but I am clueless on how to solve this 6y ^5 (sqrt)2

56. ## Calculus

Find the derivative of cos(sqrt(e^(x^3)cos(x)) I got -sin(sqrt(e^(x^3)cos(x))*((sqrt(e^(x^3)cos(x)) Do I just leave the e^(x^3)cosx alone since it's "e" or do I still have the find the derivative for it?

57. ## Math

Hi, I wanted to know how wanted to know if i was doing this step right for my homework. the question is Given rt=

58. ## calculus

pleaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaasw help can you pleaaaaase help me find the area between y=cos(4x) and y=1-cos(4x) 0

59. ## Calculus

Differentiate. f(x)=(cos x)/x I got to here: (-x sin x - cos x)/x^2 Find the equation of the tangent line to f(x)=sec x - 2 cos x at (pi/3, 1). Is the slope 3 times sqrt of 3? Equation is y=3 times sqrt of 3x - pi times sqrt of 3 +1??

60. ## Algebra 2: Radicals URGENT!!

Could some kind, saintly soul help me solve this problem? Simplify: 8w sqrt(48w^5) - x^2 sqrt(3xw^2) . . =8w(√16)(√3)(√w^4)(√w) - x^2(√3)(√x)(√w^2) =32w^3(√3w) - wx^2(√3x) not much of a "simplification" really 8w sqrt(16*3w^5) - x^2 w

61. ## calculus

Find the length of the curve given by the equation y= intergral from -pi to x of sqrt(cos(t)) dt for x between -pi and pi. I think I know to do this- at least part of it. I am using the fundamental theorem of calculus and the arc length formula, but I

62. ## Precalculus check answers help!

1.) Find an expression equivalent to sec theta sin theta cot theta csc theta. tan theta csc theta sec theta ~ sin theta 2.) Find an expression equivalent to cos theta/sin theta . tan theta cot theta ~ sec theta csc theta 3.) Simplify (tan^2 theta +

63. ## math calc

find the linear approximation to square root(a+x) for x near o. a is a constant (pos.) L(x)= sqrt(a)+1/2(a+0)^-1/2 (x-0) is this correct? use you approximation to estimate sqrt (4+0.1) How would I do this part ? Also confused with this? find the linear

64. ## Trigonometry

If cos(a)=1/2 and sin(b)=2/3, find sin(a+b), if 1) Both angles are acute; Answer: (sqrt(15)+2)/6 ii) a is an acute angle and pi/2 < b < pi; Answer: (2-sqrt(15))/6 2. Find the exact value of the six trigonometric functions of 13pi/12. Partial answer:

65. ## Trig

Compute inverse functions to four significant digits. cos^2x=3-5cosx rewrite it as.. cos^2x + 5cosx -3=0 now you have a quadratic, solve for cos x using the equation cosx=(-5 -+ sqrt (25 +12)/2

66. ## TRIG

what is the exact value of sin^2 pi/6-2 sin pi/6 cos pi/6 +cos^2 (-pi/6)? a) 2- sqrt 3 b) 2- sqrt 3/ 2 c) 2+ sqrt 3/2 d) 2+ sqrt 3 I am not sure how to work this out and would appreciate you how to show me the process. Thank you in advanced!!!!!!!

67. ## maths

Find all possible solutions in the range 0°≤ x ≤ 180° of the following equations: (a) cos x = sqrt(2) / 2 (b) tan x = sqrt(3) / 3 (c) sin x = sin60° (d) cos x = -1/2 (e) sin x = -1/2

68. ## MATHS

Find all possible solutions in the range 0°≤ x ≤ 180° of the following equations: (a) cos x = sqrt(2) / 2 (b) tan x = sqrt(3) / 3 (c) sin x = sin60° (d) cos x = -1/2 (e) sin x = -1/2

69. ## Math

cos(2 tan^-1 1/3) cos(sin^-1 1/5 +cos^-1 1/3) For this one I got the answer to be sqrt 24/15 -sqrt 8/15, is that right? I have no clue how to start the first one

70. ## Calc II

For the following question, we need to find the length of the polar curve: r= 2/(1-cosx) from pi/2

1) Evaluate (if possible) the sine, cosine, and tangent of the angles without a calculator. a) 10pi/3 Sin = -sqrt 3/2 Cos = -1/2 Tan = sqrt 3 Are these correct ? I do not understand when to make them negative. b) 17pi/3 Sin = -sqrt 3/2 Cos = 1/2 Tan = -

72. ## Calc

1. The problem statement, all variables and given/known data cos(x) = -2 I was trying to solve that problem ignoring what people say about it not being defined and got a number strangely. I showed step by step so you can tell me what I did wrong as I don't

73. ## Trigonometry

I need help with I just can't seem to get anywhere. this is as far as I have got: Solve for b arcsin(b)+ 2arctan(b)=pi arcsin(b)=pi-2arctan(b) b=sin(pi-2arctan(b)) Sub in Sin difference identity let 2U=(2arctan(b)) sin(a-b)=sinacosb-cosasinb

74. ## Math

How do you find a square root of a number that's not a perfect square? I'm very confused. The book doesn't explain it too well. You can approximate it or simplify it in terms of (products of) square roots of smaller numbers. E.g. consider sqrt[117] The

75. ## Surds

Solve in the exact form. (sqrt of 4x+1)+(sqrt of x+1)=2 Someone showed me to do this next: Square both sides..so.. 4x+1+2((sqrt of 4x+1)•(sqrt of x+1))=4 I do not understand where the 2 come from ..and why do we need to multiply the sqrt of 4x+1 and sqrt

76. ## Math sin/cos

On a piece of paper draw and label a right triangle using the given sides, solve for the unknown side and write the trigonometric functions for angles A and B, if a=5 and c=7. I already found side b which equals 2 sqrts of 6. Now I need to find the sin/cos

ok, i tried to do what you told me but i cant solve it for c because they cancel each others out! the integral for the first one i got is [sin(c)cos(x)-cos(c)sin(x)+sin(x)+c] and the integral for the 2nd one i got is [-sin(c)cos(x)+cos(c)sin(x)-sin(x)+c] I

78. ## math,algebra,help

Directions are simplify by combining like terms. x radiacal 18 -3 radical 8x^2 can someone show me how to do these types of problems. thanks I cant determine the second term. For the first, I think you meant x sqrt(18) which reduces to x sqrt (9*3) or 3x

79. ## MATH

cos(x)=2 and sin(x)=5 Thanks for your previous answers mathmate. No. It's not a typo. I was wondering if someone could explain to me when in real life would I need to solve such problems, or similar, besides answering problems from a textbook. When ever I

80. ## Pre Calc.

Use the sum or difference identity to find the exact value of sin255 degrees. My answer: (-sqrt(2)- sqrt(6)) / (4) Find the value of tan (alpha-beta), if cos alpha= -3/5, sin beta= 5/13, 90

81. ## Homework Help Calculus

Find the linear approximation L(x)of the function f(x)=cos(pi/(6)x) at the point x=1 and use it to estimate the value of cos(13pi/72). Here's what I did so far: L(x)=sqrt(3)/2-1/12pi(x-1)+0((x-1)^2) How do I find cos(13pi/72)

82. ## Calc

Can anyone help me find the derivative of these functions? y = x^2x y = x^-cos(x) y = ln(7x^2 + 5y^2) sqrt(3x+y)=2+x^2y^2 ysec(x) = 3xtan(y) y = arctan[(sqrt((1 + x)/(1 - x)))]

83. ## Trigonometry

Find all the angles θ in the interval [-2pi, 2pi] for which cos(3θ) = 1/sqrt(2) I'm not sure why I would have to look for angles in 3 revolutions of the circle (3 positive, 3 negative). Also how would I convert cos(3θ) = 1/sqrt(2) to a radian value? Do

84. ## calculus

find max, min and saddle points of the give function f(x,y)=sin(x)+sin(y)+sin(x+y) 0

85. ## Calculus

Hi, been tearing my hair out over this question. I think I'm on the right track, but just not sure how to finish it. Anyway, here it is: A particle is moving along the ellipse 4x^2 + 16y^2 = 64. At any time 'T' its x- and y-coordinates are given by x =

86. ## find dy/ds

y = s*square root of(1-s^2) + cos inverse(s) Just give me some hints and I will do it. Thanks. You have y = s*square root of(1-s^2) + cos inverse(s) which I would write as y = s*sqrt(1-s2) + cos-1(s) and you want dy/ds For the first term use the product

87. ## mathematics

Just a few questions im having trouble with 1. sqrt(6-3x)-2=0 A. 2/3 B. 2 C. 10/3 D. 4 2. Using a reference triangle, find the exact value of the expression: sin(cos^-1(1-x)) A. sqrt(x(2+x) B.1/sqrt(x(2+x)) C.1/sqrt(2+x) D.sqrt(x(2-x)) 3. The ladder of a

88. ## Pre-Calc

Find the point (x, y) on the unit circle that corresponds to the real number 5pi/6. Use it to evaluate cos n. Is cos n = (-sqrt(3)/2)?

89. ## Precalculus

Solve Cos^2(x)+cos(x)=cos(2x). Give exact answers within the interval [0,2π) Ive got the equation down to -cos^2(x)+cos(x)+1=0 or and it can be simplified too sin^2(x)+cos(x)=0 If you could tell me where to go from either of these two, it would be great

90. ## Calculus

Use a trig identity to combine two functions into one so you can solve for x. (The solution should be valid for any value of t). 3cos(t) + 3*sqrt(3)*sin(t)=6cos(t-x) I know that 6 cos(t-x) can be 6(cos(t)cosx(x)+sin(t)sin(x)) I don't know where to go from

91. ## math

determine the area of triangle abc when side ab= square root of x, side bc= square root of x, and side ca= the square root of the square root of x. So how do I solve it. How do I add the square root of x + the square root of x + the square root of the

92. ## 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).

93. ## trig question

Compute inverse functions to four significant digits. cos^2x=3-5cosx cos^2x + 5cosx -3=0 now you have a quadratic, solve for cos x using the equation cosx=(-5 -+ sqrt (25 +12)/2 the back of the book says .9987+2kpi and -.09987+2kpi when i do it i don't get

1. solve sqrt (11-x) = sqrt(x-7) choices are 6,7,8 or9 I think according to my calcs the answer is (9) The range of f(x) = sqrt(3x-6) - 2 answers would be y= (-2) y> (-2) y

95. ## rationalizing

sqrt(18) - sqrt(17) How does this expression equal 1/(sqrt(18) + sqrt(17)) ? How would you change it like that? And why is this good to use when not using a calculator?

96. ## trig

2sin(x)cos(x)+cos(x)=0 I'm looking for exact value solutions in [0, 3π] So I need to find general solutions to solve the equation. But do I eliminate cos(x), like this... 2sin(x)cos(x)+cos(x)=0 2sin(x)cos(x)= -cos(x) 2sin(x) = -1 sin(x) = -1/2 at 4pi/3

97. ## math

Suppose z is a complex number such that z^5 = -\sqrt{3} + i and z = \sqrt[5]{2} ( \cos n^{\circ} + i \sin n^{\circ}) , where 270 < n < 360 . Find the exact value of n .

98. ## MATH

Solve the equation algebraically for x where 0

99. ## MATH

For each set of numbers, draw your own number line on a piece of paper, taking care to plot each pair of irrational numbers. Then write a statement comparing the position of the two given numbers on a number line. Also write an inequality comparing the two

100. ## math,help,algebra I

I need help can someone help me get unstuck and let me know if i am correct.thank you. solve by completing the square. 4x^2+2x-3=0 this is what i am doing: i used the quadratic equation. so where i am is in this step: x = (-2 (+-) sqrt (-44))/(8) from this