trig help much appreciated! :))

posted by .

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  = tan2  sin2 .
5. Prove that tan  sin  + cos  = sec .
6. Prove that = cos  + sin .
7. Prove that .
8. Prove that = cos  – cot  cos .
9. Find a counterexample to shows that the equation sec  – cos  = sin  sec  is not
an identity.
sin cos
tan sin cos tan
2 2 ω ω
ωω ω ω

+
1 + tan
1 tan
sec + 2tan
1 tan
2
2
θ
θ
θ θ
− − θ
=
tan cos + sin
sin

10. Write tan as a function of  only.
11. Write cos as a function of  only.
12. Write cos(–83°) as a function of a positive angle.
13. Write sin(125°) in terms of its cofunction. Make sure your answer is a function
of a positive angle.
14. Find the exact value of sin(195°).

  • trig help much appreciated! :)) -

    no ideas on any of these? Also you have some major typos and/or formatting issues.

    I'll do a couple. Maybe you can clean up the post and indicate where you get stuck on the others.

    #2
    cos 2x – 3sin x cos 2x = 0
    (1-3sinx)cos2x = 0
    so, either
    cos2x=0 ==> x = pi/4 or 3pi/4
    sinx = 1/3 ==> x=arcsin(1/3) or pi-arcsin(1/3)

    #3
    tan2 x + tan x – 1 = 0
    tanx = (-1±√5)/2
    so find arctan of those two values and recall that tan is positive in QI,QIII and negative in QII,QIV

  • trig help much appreciated! :)) -

    alright, I will. Thanks

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. 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 = - …
  2. 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 …
  3. Trig

    1. Establish the identity: sin(theta+3pi/2)=-cos(theta) 2. Find the exact value of 2(theta) if sin(theta)=5/13 3. Show that: csc2(theta)-cot2(theta)=tan(theta) 4. Find the exact value of tan(cos^-1(square root of 3/2) 5. Approximate …
  4. Trigonometry

    Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. Please explain.
  5. trigonometry

    5. Find the complete exact solution of sin x = -√3/2. 9. Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. 21. Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. …
  6. trigonometry

    5.Find the complete exact solution of sin x = -√3/2. 10. Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. 12. Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. …
  7. Trigonometry

    1.Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. 6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y 10.Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that …
  8. 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 tan(x) …
  9. Trig hep, please? Thank you!

    1. Find the exact value of sin(195(degrees)) 2. If cot2(delta)=5/12 with 0(<or =)2(delta)pi, find cos(delta), sin(delta) , tan(delta). 3.find the exact value of sin2(x) if cos(x)= 4/5. (X is in quadrant 1) 4. Find the exact value …
  10. Pre-Cal (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 …

More Similar Questions