The mirror image of the parabola y2 = 4x in the tangent to the parabol...
Mirror Image of the Parabola
The given parabola equation is y^2 = 4x. We need to find the mirror image of this parabola with respect to the tangent to the parabola at the point (1,2).
To find the mirror image, we can reflect the given parabola across the tangent line. Let's find the equation of the tangent line first.
Finding the Tangent Line
To find the equation of the tangent line at the point (1,2), we need to find the slope of the tangent.
We differentiate the equation of the parabola with respect to x to find the slope of the tangent at any point on the parabola.
Differentiating y^2 = 4x with respect to x:
2y * dy/dx = 4
dy/dx = 4 / (2y)
dy/dx = 2/y
At the point (1,2), y = 2. Substituting this into the equation, we get:
dy/dx = 2/2 = 1
So, the slope of the tangent at the point (1,2) is 1.
Using the point-slope form of a line, we can write the equation of the tangent line:
y - y1 = m(x - x1)
y - 2 = 1(x - 1)
y = x + 1
Reflecting the Parabola
Now, let's reflect the given parabola across the tangent line.
The mirror image of any point (x, y) with respect to the line y = x + 1 is (y, x).
So, the mirror image of the parabola equation y^2 = 4x with respect to the tangent line is (x - 1)^2 = 4(y - 1).
Therefore, the correct answer is option 'C': (x - 1)^2 = 4(y - 1).