MODIFIED: Find the equation of the tangent to the ellipse variable_97²/16 + variable_97²/9 = 1 that passes through the point (8, 0).

Answer: The equations of the tangents are y=34x−23y = \frac{\sqrt{3}}{4}x - 2\sqrt{3} and y=−34x+23y = -\frac{\sqrt{3}}{4}x + 2\sqrt{3}.

Step-by-step solution

Step 1: Identify the equation of the ellipse and the external point

The given equation of the ellipse is x216+y29=1\frac{x^2}{16} + \frac{y^2}{9} = 1. By comparing this with the standard form of an ellipse x2a2+y2b2=1\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1, we can identify the values of a2a^2 and b2b^2. The point through which the tangent passes is (8,0)(8, 0).

Step 2: Use the condition for tangency

The general equation of a tangent to an ellipse is y=mx+cy = mx + c. For this line to be tangent to the ellipse x2a2+y2b2=1\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1, the condition c2=a2m2+b2c^2 = a^2m^2 + b^2 must be satisfied. From the ellipse equation, we have a2=16a^2 = 16 and b2=9b^2 = 9.

Step 3: Substitute values and the external point into the tangent equation

Substitute a2=16a^2 = 16 and b2=9b^2 = 9 into the tangency condition, giving c2=16m2+9c^2 = 16m^2 + 9. Since the tangent passes through the point (8,0)(8, 0), we substitute x=8x=8 and y=0y=0 into the tangent equation y=mx+cy = mx + c, which gives 0=m(8)+c0 = m(8) + c, so c=−8mc = -8m.

Step 4: Solve for the slope 'm'

Now, substitute c=−8mc = -8m into the tangency condition c2=16m2+9c^2 = 16m^2 + 9. This results in an equation solely in terms of mm. Solving this quadratic equation for mm will give us the slopes of the two possible tangent lines.

Step 5: Find the corresponding 'c' values

For each value of mm found, we can calculate the corresponding value of cc using the relation c=−8mc = -8m. This will give us two pairs of (m,c)(m, c) values, each corresponding to a unique tangent line.

Step 6: Write the equations of the tangent lines

Substitute the calculated values of mm and cc back into the general tangent equation y=mx+cy = mx + c to obtain the equations of the two tangent lines.

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