138k views
3 votes
The line with equation 2x + y - 5 = 0 is a tangent to the circle with equation (x-3)² (y-p)² = 5. Write down the coordinates of the center of the circle in each case.

User Algometrix
by
7.6k points

1 Answer

4 votes

Final answer:

To find the coordinates of the center of the circle, you can rearrange the equation of the line in the standard form of a line equation, substitute it into the equation of the circle, and solve for the unknown variable. In this case, the center of the circle is located at (3, 8.125).

Step-by-step explanation:

To find the coordinates of the center of the circle, we can start by rearranging the equation of the line in the standard form of a line equation, which is y = mx + c.

In this case, the equation 2x + y - 5 = 0 can be rearranged to y = -2x + 5.

Next, we substitute this equation into the equation of the circle to find the coordinates of the center.

(x-3)² (y-p)² = 5

Replacing y with -2x + 5, we get:

(x-3)² (-2x + 5 - p)² = 5

Since the line is a tangent to the circle, the discriminant of this equation should be equal to 0.

By expanding and simplifying, we have:

4x² - 20x + 25 - 4px + 6x² - 30x + 25 = 5

Combining like terms, we get:

10x² - 50x + 45 - 4px = 0

For the discriminant to be 0, we have:

(-50)² - 4 * 10 * (45 - 4p) = 0

Simplifying further, we obtain:

2500 - 40(45 - 4p) = 0

Expanding and simplifying, we have:

2500 - 1800 + 160p = 0

Combining like terms, we get:

160p = 1300

Solving for p, we find:

p = 1300/160 = 8.125

Therefore, the center of the circle has coordinates (3, 8.125).

User JakubW
by
8.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories