Question 1203784
{{{f(x) = 5sec(3x)}}}

 stretching factor: Stretched vertically by {{{5}}}

period:  {{{(2pi)/3}}}

Vertical asymptotes 

{{{x=pi/2+(2pi/3)n}}}
{{{x=pi/6+(2pi/3)n}}} where {{{n}}} is an integer

in two period distance are

{{{1/4}}} and {{{3/4 }}}of the distance between{{{ 0}}} and {{{(2pi)/3}}}, and the distance between {{{0 }}}and {{{-(2pi)/3}}}

{{{x=(1/4)(0+(2pi)/3)=pi/6}}}
{{{x=(3/4)(0+(2pi)/3)=3pi/6=pi/2}}}
similarly
{{{x=-pi/6}}}
{{{x=-pi/2}}}

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