Math

Solve the question: sin(2x)=cos(x), for values of x between 0 and 2 Pi

  1. 👍 0
  2. 👎 0
  3. 👁 87
asked by Ryomasa
  1. You'll find it very helpful to remember that sin(2x)=2sin(x)cos(x) here, since this means that you're trying to find all the solutions of 2sin(x)cos(x)=cos(x). These will be equal under two possible scenarios: firstly if cos(x)=0 (since both sides will be zero), and secondly if 2sin(x)=1, or sin(x)=0.5 (i.e. after you've cancelled out the cos(x) terms from both sides). Solve both of those equalities for all possible values between 0 and 2pi, and you've done it. I think you'll find there are four of them - two from each scenario.

    1. 👍 0
    2. 👎 0
    posted by David Q

Respond to this Question

First Name

Your Response

Similar Questions

  1. 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 +

    asked by hayden on February 23, 2009
  2. Calculus - MathMate Please help

    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

    asked by K on November 29, 2010
  3. math

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

    asked by mathstudent on December 19, 2006
  4. 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(a-b) = sin(a)cos(b) - cos(a)sin(b)

    asked by Pablo on November 26, 2006
  5. Trigonometry desperate help, clueless girl here

    2. solve cos 2x-3sin x cos 2x=0 for the principal values to two decimal places. 3. solve tan^2 + tan x-1= 0 for the principal values to two decimal places. 4. Prove that tan^2(x) -1 + cos^2(x) = tan^2(x) sin^2 (x). 5.Prove that

    asked by Suzy on August 16, 2013
  6. 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

    asked by Valerie on February 18, 2007
  7. 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. sin2Į = (sqrt 3)/2 2. sin^2Į =

    asked by anon on March 3, 2011
  8. 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

    asked by Paul C on November 26, 2006
  9. 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

    asked by Gary on March 9, 2011
  10. Trigonometry

    Solve the equation for solutions in the interval 0

    asked by Renee on March 7, 2016
  11. 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) =

    asked by Anonymous on November 8, 2007

More Similar Questions