posted by .

Solve the equation in the given Domain:

1-cos theta/ sin theta = sqr3, 0degrees <or equal to theta < 369 degrees

cos4x + cos 2x =0, 0<or equal to x < pi

  • Math/trig -

    Recall that

    1-cos theta/ sin theta = tan(theta/2)

    so, we want tan(theta/2) = sqrt(3)
    theta/2 = 60
    theta = 120

    Note that theta/2 = 240 also works, but that requires theta=480, outside the domain given.

    2cos^2(2x) - 1 + cos(2x) = 0
    (2cos2x - 1)(cos2x + 1) = 0

    cos2x = 1/2, so 2x = 60,300, so x=30,150
    cos2x = -1, so 2x = 180, so x=90

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Trig

    Which expression equivalent to: cos(theta + pi/2). A)cos theta B)-cos theta C)sin theta D)-sin theta my book doesnt give examples of this but my crack at it would be C b/c distributive property?
  2. Algebra II

    Which of the following expressions are not equal to 1?
  3. Calculus

    I wanted to confirm that I solved these problems correctly (we had to convert the polar curves to Cartesian equations). 1.rcos(theta)=1 x=1 2.r=2*sin(theta)+2*cos(theta) r^2=2rsin(theta)+2rcos(theta) x^2+y^2=2y+2x (a little unsure …
  4. 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 …
  5. Precalculus(NEED HELP ASAP PLEASE!!)

    Solve: sin(theta)cos(theta)-sin(theta)−cos(theta)+1 = 0, 0 < or equal to theta < 2pi Solution Set: ____________ ?
  6. trig

    Hi, I need to find the domain and rnge of the following: 1. X= 1/2 (cos theta + theta sin theta) Y=1/2 (sin theta - theta cos theta) total guess here, but here goes Domain cos theta = +/- 1 and domain sin theta = +/- 1 so domain theta …
  7. Trigonometry

    Thank you STEVE!!!!! Suppose that Cos (theta) = 1/square root 2 if 0<equal to theta , pi/2 then sin(theta) = tan (theta) = If 3pi/2 less than equal to theta , 2pi then sin(theta) = tan (theta) = I know the trig functions but I feel …
  8. trig

    If sin theta is equal to 5/13 and theta is an angle in quadrant II find the value of cos theta, sec theta, tan theta, csc theta, cot theta.
  9. Math Trig Help

    sin theta = x/3, with theta in the first quadrant, find the expression for cos theta and tan theta. Answers will be in algebraic terms of x. Give exact answers with 0 < theta <pi/2 (0 less than or equal to theta, less than or …
  10. Precalculus

    Circle O below has radius 1. Eight segment lengths are labeled with lowercase letters. Six of these equal a trigonometric function of theta. Your answer to this problem should be a six letter sequence whose letters represent the segment …

More Similar Questions