I don't know which command to determine the tangent lines that are parallel to the line $x=0$ (i.e. the y-axis) in Polar Coordinates. Can you help me please to give me some suggestions?

I attach some code which I have written:

theta = 45;
the = theta*Pi/180;
alp = 2;
gc = Sqrt[1 + alp*Sin[x - the]*Sin[x - the]];
yy = 1./gc;
PolarPlot[yy, {x, 0, 2*Pi}, PolarAxes -> True, 
 PolarTicks -> {"Degrees", Automatic}, PolarGridLines -> True, 
 Mesh -> 15, MeshStyle -> Directive[PointSize[Large], Red]]

I don't know which command to determine the tangent lines that are parallel to the line $x=0$ (i.e. the y-axis) in Polar Coordinates. Can you help me please to give me some suggestions?

I attach some code which I have written:

theta = 45;
the = theta*Pi/180;
alp = 2;
gc = Sqrt[1 + alp*Sin[x - the]*Sin[x - the]];
yy = 1/gc;
PolarPlot[yy, {x, 0, 2*Pi}, PolarAxes -> True, 
 PolarTicks -> {"Degrees", Automatic}, PolarGridLines -> True, 
 Mesh -> 15, MeshStyle -> Directive[PointSize[Large], Red]]

I don't know which command to determine the tangent POINT that is parallel to the line x=0 (or y ) in Polar System, can you help me please to give me some suggestions?

I attach some codes which I have written.

theta = 45;
the = theta*Pi/180;
alp = 2;
gc = Sqrt[1 + alp*Sin[x - the]*Sin[x - the]];
yy = 1./gc;
PolarPlot[yy, {x, 0, 2*Pi}, PolarAxes -> True, 
 PolarTicks -> {"Degrees", Automatic}, PolarGridLines -> True, 
 Mesh -> 15, MeshStyle -> Directive[PointSize[Large], Red]]

I don't know which command to determine the tangent lines that are parallel to the line $x=0$ (i.e. the y-axis) in Polar Coordinates. Can you help me please to give me some suggestions?

I attach some code which I have written:

theta = 45;
the = theta*Pi/180;
alp = 2;
gc = Sqrt[1 + alp*Sin[x - the]*Sin[x - the]];
yy = 1./gc;
PolarPlot[yy, {x, 0, 2*Pi}, PolarAxes -> True, 
 PolarTicks -> {"Degrees", Automatic}, PolarGridLines -> True, 
 Mesh -> 15, MeshStyle -> Directive[PointSize[Large], Red]]