How do you solve sec xx = cosec 3/4pi34π for the range value of 0 <= x <= 2pi0x2π ?

1 Answer
Apr 1, 2018

x=pi/4, (7pi)/4x=π4,7π4

Explanation:

First, let's evaluate csc((3pi)/4).csc(3π4). Knowing that cscx=1/sinx, csc((3pi)/4)=1/sin((3pi)/4)cscx=1sinx,csc(3π4)=1sin(3π4)

Now, sin((3pi)/4)=sqrt(2)/2, csc((3pi)/4)=1/(sqrt(2)/2)=2/sqrt(2)sin(3π4)=22,csc(3π4)=122=22

So, we are really just being asked to solve

secx=2/sqrt(2)secx=22

Recalling that secx=1/cosx:secx=1cosx:

1/cosx=2/sqrt(2)1cosx=22

Invert both sides to get the cosine on top:

cosx=sqrt(2)/2cosx=22

In the interval [0, 2pi],[0,2π], this holds true for x=pi/4, (7pi)/4x=π4,7π4