Question 1184208

given:

the ellipse {{{ x^2/10 + y^2/8 =1 }}} 
a point  is at the distance of {{{3}}} units from the center of ellipse


let a point  P({{{a*cos (theta)}}} ,{{{b*sin(theta)}}} )  

in 
{{{a=sqrt(10)}}}
{{{b=sqrt(8)}}}

 P({{{sqrt(10)cos(theta)}}} ,{{{sqrt(8)sin(theta)}}} )  


its distance from ({{{0}}},{{{0}}}) is {{{3}}} 

 {{{10cos^2 (theta) +8sin^2(theta )=9}}}

{{{18sin^2(theta )=9}}}....divide by {{{9}}}

 {{{2cos^2(theta) =1}}}

{{{cos^2(theta) =1/2}}}

{{{cos(theta) =1/sqrt(2)}}}

{{{theta =pi/4}}}