How do you graph y=sec(3x-(2pi)/3)-1y=sec(3x2π3)1?

1 Answer
Jul 27, 2018

See graph and explanation.

Explanation:

A sec value notin [ - 1, 1 )[1,1)

y = sec ( 3 x - 2/3pi ) - 1 notin { -2 0 )y=sec(3x23π)1{20)

As sec ( .. ) = 1/ cos ( .., )

the asymptotes are given by the zeros of cos ( 3x - 2/3pi )cos(3x23π)

rArr the asymptotes are

3x - 2/3 pi = ( 2 k + 1 ) pi/2, k = 0, +-1, +-2, +-3, ..., giving

x = 1/3 ( ( 2 k + 1 ) pi/2 + 2/3 pi ) = (( 3 ( 2 k + 1 ) + 4 ) pi/18

= 1/18 (6 k + 7) pi = ....- 5/18pi, 1/18pi, 7/18pi, ...

See graph, with two asymptotes, near O.

graph{((y+1)cos(3x-2/3pi)-1)(y)(y+2)(x+5/18 pi+0.001y)(x-1/18pi+0y)=0}