Question 1174826
Let's solve this problem step-by-step.

**1. Understand Contact of Third Order**

* Two curves have contact of third order at a point if they have the same value, the same first derivative, the same second derivative, and the same third derivative at that point.

**2. Parabola Equation**

* Since the parabola has contact at the origin, and we need a general form, we'll use the form:
    * y = Ax² + Bx³

    * Note that the parabola must pass through the origin (0,0) and the tangent at the origin must be along the x axis.

**3. Conic Equation**

* The given conic is:
    * ax² + 2hxy + by² + 2gx + 2fy + c = 0

**4. Contact at the Origin**

* Since both curves pass through the origin (0, 0), we have c = 0.
* Thus the conic equation becomes:
    * ax² + 2hxy + by² + 2gx + 2fy = 0

**5. Derivatives**

* **Parabola:**
    * y = Ax² + Bx³
    * y' = 2Ax + 3Bx²
    * y'' = 2A + 6Bx
    * y''' = 6B

* **Conic:**
    * To find derivatives, we'll use implicit differentiation.
    * ax² + 2hxy + by² + 2gx + 2fy = 0
    * Differentiate w.r.t x: 2ax + 2hy + 2hx y' + 2by y' + 2g + 2fy' = 0
    * At (0, 0): 2g + 2fy' = 0 => y' = -g/f
    * If the tangent is along the x axis then y' = 0, thus g = 0.
    * Conic equation now is: ax² + 2hxy + by² + 2fy = 0.
    * 2ax + 2hy + 2hxy' + 2byy' + 2fy'=0.
    * Differentiate again. 2a + 2hy' + 2hy' + 2hxy'' + 2by'y' + 2byy'' + 2fy'' = 0.
    * At (0,0) with g=0 and y'=0, 2a + 2fy''=0, thus y'' = -a/f
    * Differentiate again. 2hy'' + 2hy'' + 2hy'' + 2hxy''' + 4by'y'' + 2by'y'' + 2byy''' + 2fy''' = 0
    * At (0,0) with g=0 and y'=0, 6hy'' + 2fy''' = 0, thus y''' = -3hy''/f = 3ha/f².

**6. Equate Derivatives at (0, 0)**

* **y'(0):**
    * Parabola: 0
    * Conic: 0 (since g=0)
* **y''(0):**
    * Parabola: 2A
    * Conic: -a/f
    * Therefore, 2A = -a/f => A = -a/(2f)
* **y'''(0):**
    * Parabola: 6B
    * Conic: 3ha/f²
    * Therefore, 6B = 3ha/f² => B = ha/(2f²)

**7. Parabola Equation**

* Substitute A and B into the parabola equation:
    * y = (-a/(2f))x² + (ha/(2f²))x³
    * y = (-ax²f + hax³)/(2f²)
    * 2f²y = -ax²f + hax³
    * 2f²y + ax²f - hax³ = 0

**Final Equation**

The equation of the parabola is:

**2f²y + ax²f - hax³ = 0**