1.
Persamaan lingkaran dengan pusat (0,0) dan jari-jari 3 adalah...
Correct Answer
C. X2 + y2 = 9
Explanation
The equation of a circle with center (0,0) and radius 3 is x^2 + y^2 = 9. This equation represents all the points (x,y) that are a distance of 3 units away from the origin (0,0). By substituting different values of x and y into the equation, we can verify that the equation holds true for all points on the circle. Therefore, x^2 + y^2 = 9 is the correct answer.
2.
Jari-jari dan pusat lingkaran yang memiliki persamaan x2 + y2 + 4x − 6y − 12 = 0 adalah...
Correct Answer
A. 5 dan (−2, 3)
Explanation
The equation of the circle is in the form (x-h)^2 + (y-k)^2 = r^2, where (h,k) is the center of the circle and r is the radius. By comparing the given equation x^2 + y^2 + 4x - 6y - 12 = 0 with the standard form, we can see that the center of the circle is (-2, 3) and the radius is 5. Therefore, the correct answer is 5 and (-2, 3).
3.
Persamaan lingkaran yang berpusat di (2,-3) dengan jari-jari 7 adalah...
Correct Answer
C. X2 + y2 - 4x + 6y - 36 = 0
Explanation
The equation of a circle with center (h,k) and radius r is given by (x-h)^2 + (y-k)^2 = r^2. In this case, the center is (2,-3) and the radius is 7. Plugging these values into the equation, we get (x-2)^2 + (y+3)^2 = 7^2. Expanding this equation gives x^2 + y^2 - 4x + 6y - 36 = 0. Therefore, the correct answer is x^2 + y^2 - 4x + 6y - 36 = 0.
4.
Jari - jari lingkaran x2 + y2 - 6x - 4y - 3 = 0 adalah...
Correct Answer
A. 4
Explanation
The given equation represents a circle in the form of (x - a)2 + (y - b)2 = r2, where (a, b) is the center of the circle and r is the radius. By comparing the given equation with the standard form, we can determine that the center of the circle is (3, 2) and the radius is √3. Since the question asks for the value of the radius, the correct answer is 4.
5.
Pusat dan jari - jari lingkaran dari persamaan x2 + y2 - 4x + 12y - 9 = 0 adalah ...
Correct Answer
C. (2,-6) dan 7
Explanation
The given equation represents a circle in the coordinate plane. The general equation of a circle is (x - h)^2 + (y - k)^2 = r^2, where (h, k) represents the coordinates of the center of the circle and r represents the radius. By comparing the given equation with the general equation, we can determine that the center of the circle is (2, -6) and the radius is 7. Therefore, the correct answer is (2, -6) dan 7.
6.
Perhatikan gambar di bawah ini!
Correct Answer
D. X2 + y2 = 64
Explanation
The given answer, x2 + y2 = 64, is correct because it follows the pattern of the other equations. Each equation represents a circle with a different radius. The equation x2 + y2 = 64 represents a circle with a radius of 8, which is the square root of 64. Therefore, it is the correct equation that fits the pattern of the other equations.
7.
Persamaan lingkaran yang berpusat di (3,2) dan berjari - jari 4 adalah ...
Correct Answer
A. X2 + y2 - 6x + 4y - 3 = 0
Explanation
The equation of a circle with center (h,k) and radius r is (x-h)^2 + (y-k)^2 = r^2. In this case, the center is (3,2) and the radius is 4. Plugging these values into the equation, we get (x-3)^2 + (y-2)^2 = 4^2, which simplifies to x^2 + y^2 - 6x + 4y - 3 = 0.
8.
Diberikan persamaan lingkaran sebagai berikut: x2 + y2 −2x + 4y + 1 = 0. Jika pusat lingkaran adalah P(a,b) maka nilai dari 10a - 5b =...
Correct Answer
E. 20
Explanation
The equation of the circle can be rewritten as (x-1)² + (y+2)² = 4. Comparing this with the standard equation of a circle, (x-h)² + (y-k)² = r², we can see that the center of the circle is at point P(1, -2) and the radius is 2.
To find the value of 10a - 5b, we can substitute the coordinates of the center into the expression.
10a - 5b = 10(1) - 5(-2) = 10 + 10 = 20.
Therefore, the correct answer is 20.
9.
Persamaan lingkaran yang berpusat di P(3, – 4) dan menyinggung sumbu x adalah …
Correct Answer
E. (x – 3)2 + (y + 4)2 = 16
Explanation
The given equation represents a circle centered at point P(3, -4) and touches the x-axis. The general equation of a circle is (x - h)^2 + (y - k)^2 = r^2, where (h, k) represents the center of the circle and r represents the radius. In this case, the center is (3, -4) and the radius is 4 (since 4^2 = 16). Therefore, the correct equation is (x - 3)^2 + (y + 4)^2 = 16.
10.
Persamaan lingkaran pada gambar berikut adalah...
Correct Answer
B. X2 + y2 = 25
Explanation
The equation x^2 + y^2 = 25 represents a circle with a radius of 5 units. This is because the equation of a circle centered at the origin is x^2 + y^2 = r^2, where r is the radius. In this case, r = 5, so the equation becomes x^2 + y^2 = 25.