Trig

Can somebody please help me find the domain of:

1 / cos4x

If there are any working out, could you be kind enough to show your steps? Thankyou. All help is of course, appreciated.

  1. 👍 0
  2. 👎 0
  3. 👁 145
asked by sqleung
  1. 1/cos4x is real as long as cos4x is not equal to zero.

    the period of cos4x is 2pi/4 or pi/2 (90º)

    so the first time that cos4x is zero is at x=pi/8
    repeatedly adding or subtracting pi/4 (45º) to this will give us another zero.

    so the domain for 1/cos4x is
    x is any real number except x = pi/8 ± kpi/4 where k is an integer.

    Of course y = 1/cos4x is the same as
    y = sec 4x, which would have vertical asymptotes at the values of x described above.

    1. 👍 0
    2. 👎 0
    posted by Reiny

Respond to this Question

First Name

Your Response

Similar Questions

  1. Math-trigonometry

    Several questions from my homework, any are appreciated. Thanks! Solve: 1) sinx-tanx=0 2) 3csc^2x=4 Find all solutions within (0,2pi) 3) cos4x(cosx-1)=0 4) cos4x-7cos2x=8 Use inverse functions where necessary to find solutions

    asked by Michael on January 12, 2011
  2. Pre-Calculus

    Find all solutions to the equation in the interval [0, 2pi) cos4x-cos2x=0 So,this is what i've done so far: cos4x-cos2x=0 cos2(2x)-cos2x (2cos^2(2x)-1)-(2cos^2(x)-1) No idea what to do next.

    asked by Maria on March 19, 2012
  3. trig

    Prove that cos4x=8cos^4x-8cos^2x+1 so I'm guessing you begin with the left side cos4x=cos2(2x) then im kinda lost

    asked by Natash on November 23, 2008
  4. Math

    The domain of g(x) is -1< x < 9 What is the domain of g(x - 4) I know the Domain: ?< x

    asked by Rai on October 10, 2014
  5. Math

    Find the requested function and state its domain: f(x)= 4x+3 g(x)=4x-5 Find f/g and its domain. So I did 4x+3/4x-5, so the 4x's cancel out and 3/-5 is left. So my answer is 3/-5. Is this correct Now I just need to find the domain

    asked by Hannah on October 7, 2010
  6. Math

    Find the requested function and state its domain: f(x)= 4x+3 g(x)=4x-5 Find f/g and its domain. So I did 4x+3/4x-5, so the 4x's cancel out and 3/-5 is left. So my answer is 3/-5. Is this correct Now I just need to find the domain

    asked by Hannah on October 7, 2010
  7. Math

    1. Power reducing formulas can be used to rewrite 8sin^2 xcos^2 x as 1-cos4x. True or False? 2. Find the exact value of cos15 degrees using a suitable half angle formula. square root of 2+root3 / 2? 3. Find the exact value of

    asked by mysterychicken on June 3, 2013
  8. Small Group Communication

    Regulating participation, climate making, and maintaining mutual respect are all part of the ___________. task domain, interpersonal domain, procedural domain, work domain, or life skills domain. I believe this is the life skills

    asked by Jazmyne on December 29, 2011
  9. Pre-Calc

    Suppose that f has a domain of A and g has a domain of B. (a). What is the domain of f + g? (b). What is the domain of fg? (c). What is the domain of f/g? Is there a mathematical rule or theorem for this type of question?

    asked by Stockton on August 14, 2013
  10. calculus

    for the given functions f and g, find the following and state the domain of each. f(x)=square root x; g(x)=5x-1 a. (f*g)(x)= ? what is the domain of f*g? b. (f/g)(x)=? what is the domain of f/g? please show work

    asked by anonymous on January 1, 2013

More Similar Questions