The parabola equation is and the point is .

Since the square term is , the parabola is horizontal.

Standard form of the horizontal parabola is ,

where is vertex.

Focus .

The parabola equation .

Rewrite the equation as .

Compare the above equation with .

Since , the parabola opens right.

Vertex .

Focus .

The distance between focus and the point of tangency is .

Graph:

Graph the and Focus .

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observe the graph:

is the one leg of the isosceles triangle.

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Substitute and .

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Find the point , the end point of the other leg of the isosceles triangle.

Since  is positive the parabola opens right and will be to the left of the focus.

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The tangent line passes through the points and .

The slope of tangent line is .

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The point-slope form of line equation is .

Substitute and .

The tangent line equation is .

The tangent line equation is .