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question:Construct a triangle inscribed in a given circle, given one of its angles and the median drawn from the vertex of another angle.

answer:1. **Define the Given Circle**: - Let the given circle be (k) with center (O) and radius (r). 2. **Define Triangle Properties**: - Let (A, B, C) be the vertices of the triangle. - The angle at vertex (A) is (alpha). - The median from vertex (B) to the midpoint (B_1) of side (AC) has a given length (s_b). 3. **Using Inscribed and Central Angles**: - According to the relationship between inscribed and central angles, the central angle (BOC) subtended by the arc (BC) is (2alpha). 4. **Constructing Points B and C**: - Choose any radius (OF) of the circle (k). Measure an angle (2alpha) centered at (O), ensuring the arms of this angle intersect the circle (k) at points (B) and (C). - Denote the segment (BAC). Point (A) must lie on the arc (BC) that does not include the point (F). This arc is part of the circle (i). 5. **Locating Point (B_1)**: - Point (B_1) should be the midpoint of side (AC). This implies (B_1) is a scaled-down image of (A) relative to the center (C). - Thus, (B_1) must lie on the image circle of the arc, denoted as (i_1), which is the Thales' circle using the diameter (OC). 6. **Intersection of Circles**: - To further locate point (B_1), consider the circle (k_b) centered at (B) with radius (s_b). This circle represents all possible points (B_1) such that the segment (BB_1) is (s_b). - The intersection points of (i_1) and (k_b) provide the possible positions for (B_1). 7. **Determining Point A**: - Finally, point (A) can be found as the intersection of the circle (k) with the line (CB_1). - This process defines the points of triangle (A, B, C). 8. **Number of Solutions**: - The number of possible solutions depends on the intersections of circles (i_1) and (k_b). There can be: - 2 solutions if there are two intersection points. - 1 solution if there is exactly one intersection point. - 0 solutions if there are no intersection points. # Conclusion: The solution to constructing a triangle with the given conditions can result in 2, 1, or 0 triangles depending on the intersections of the circles (i_1) and (k_b). The correctness of the construction is evident from geometric properties. (blacksquare)

question:f f(x) = 3x + 1, what is f(3)?

answer:To solve for f(3) given f(x) = 3x + 1, we substitute x with 3: [ begin{align*} f(3) &= 3(3) + 1 &= 9 + 1 &= boxed{10}. end{align*} ]

question:Let {a_n} be any geometric sequence, and let the sum of the first n terms, the first 2n terms, and the first 3n terms be X, Y, and Z respectively. Among the following equations, the one that always holds is ( ) A: X+Z=2Y B: Y(YX)=Z(ZX) C: Y^2=XZ D: Y(YX)=X(ZX)

answer:Choose the geometric sequence 1, 2, 4, and let n=1 to get X=1, Y=3, Z=7. Substitute these values to verify, only option D satisfies the condition. Therefore, the correct answer is boxed{text{D}}.

question:Place 11 balls into three boxes such that the number of balls in each box is different. What is the maximum number of balls that can be placed in the fullest box, and what is the minimum number of balls that must be placed in the fullest box?

answer:To solve this problem, we need to distribute 11 balls into three boxes such that each box contains a different number of balls, and then find both the maximum and minimum number of balls in any single box. 1. **Identify the constraints**: - We have 11 balls in total. - Each box must contain a different number of balls. - There are three boxes. 2. **Assign the minimum possible number of balls to the first two boxes**: - Let's assign 1 ball to the first box. - Let's assign 2 balls to the second box. 3. **Calculate the remaining balls for the third box**: - Remaining balls ( = 11 - 1 - 2 ). [ text{Remaining balls} = 11 - 1 - 2 = 8 ] 4. **Verification**: - Now we have assigned 1 ball to the first box, 2 balls to the second box, and 8 balls to the third box. - These assignments meet the required condition: (1 neq 2 neq 8 neq 1). Conclusion: [ boxed{8} ] 5. **Minimum possible number of balls in the box with the most balls**: - To find the minimum such maximum, we should distribute the balls as evenly as possible while maintaining that each box has a different number of balls. - We test distributing balls in closely related counts, like (2, 3, 4): [ 2 + 3 + 4 = 9 ] - Since 9 is not 11, this arrangement does not work. We need to test all remaining logical distributions: (1 + 5 + 5 = 11 quad text{(fails distinct requirement)}) (1 + 4 + 6 = 11 quad text{(works)}) - This means the new valid distribution is (1, 4, 6). Conclusion: [ boxed{5} ] Final conclusion: The most a box can contain at least of 5 balls while making it different should contain maximum 8 balls. [ boxed{8, 5} ]

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