If the equation of the hyperbola with foci (4,2)(4{,}2) and (8,2)(8{,}2) is 3x2−y2−ax+by+γ=0,3x^2 - y^2 - ax + by + \gamma = 0, then a+b+γa + b + \gamma is equal to:

Answer: 132

Step-by-step solution

Step 1: Find the center and distance between foci

The center of the hyperbola is the midpoint of the segment connecting the two foci. Given the foci are (4,2)(4{,}2) and (8,2)(8{,}2), we can calculate the center. The distance between the foci is 2c2c, which can be found using the distance formula.

Step 2: Determine the standard form of the hyperbola

Since the yy -coordinates of the foci are the same, the transverse axis is parallel to the xx -axis. This means the standard form of the hyperbola is (x−h)2a2−(y−k)2b2=1\frac{(x-h)^2}{a^2} - \frac{(y-k)^2}{b^2} = 1, where (h,k)(h,k) is the center.

Step 3: Relate a2,b2,c2a^2, b^2, c^2 and eccentricity

For a hyperbola, the relationship between aa, bb, and cc is c2=a2+b2c^2 = a^2 + b^2. The eccentricity ee is given by e=cae = \frac{c}{a}. We are given that the eccentricity e=2e = 2. Using this, we can find the values of a2a^2 and b2b^2.

Step 4: Substitute values into the standard equation

Substitute the center (h,k)=(6,2)(h,k) = (6{,}2) and the calculated values a2=4a^2 = 4 and b2=12b^2 = 12 into the standard equation of the hyperbola.

Step 5: Convert to general form and compare coefficients

Multiply the standard equation by the least common multiple of the denominators (12) to clear fractions, then expand and rearrange it into the general form 3x2−y2−ax+by+γ=03x^2 - y^2 - ax + by + \gamma = 0. By comparing the coefficients, we can find the values of aa, bb, and γ\gamma.

Step 6: Calculate a+b+γa+b+\gamma

Finally, substitute the determined values of aa, bb, and γ\gamma into the expression a+b+γa+b+\gamma to find the required sum.

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