Composite Areas Function Rainfall
1. Problem statement: Calculate areas A1, A2, A3, total area, and perimeter of the composite shape formed by three rectangles with given dimensions.
2. Calculate area A1:
A1 is a rectangle of width 12 m and height 4 m.
$$A_1 = \text{width} \times \text{height} = 12 \times 4 = 48\,m^2$$
3. Calculate area A2:
A2 is a rectangle of width 2 m and height 4 m.
$$A_2 = 2 \times 4 = 8\,m^2$$
4. Calculate area A3:
A3 is a rectangle of width 12 m and height 8 m.
$$A_3 = 12 \times 8 = 96\,m^2$$
5. Calculate total area of the composite shape:
The composite shape consists of A1, A2, and A3 combined without overlapping.
$$\text{Total area} = A_1 + A_2 + A_3 = 48 + 8 + 96 = 152\,m^2$$
6. Calculate the perimeter of the composite shape:
- Left side height: 4 + 4 + 8 = 16 m (Verify question states 15 m total, so use given distances on shape: left side total height is 4 + 4 + 8 = 16 m)
- Bottom width: 12 m
- Width along top: 12 m
Analyzing the perimeter step-by-step:
- Bottom edge: 12 m
- Right edge: height of bottom rectangle = 8 m
- Top edge: 12 m
- Left edges: sum up vertical segments: 4 + 4 + 8 = 16 m
Since the shape is compound, perimeter segments = bottom (12) + right (8) + top (12) + left (16) = 12 + 8 + 12 + 16 = 48 m
Final perimeter:
$$P = 48\,m$$
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7. Problem statement: Analyze function $$y = -\frac{3}{2}(x+2)^2 - 4$$
8. Find the axis of symmetry:
The axis of symmetry formula for vertex form $$y = a(x-h)^2 + k$$ is $$x = h$$.
Here, $$h = -2$$
Axis of symmetry:
$$x = -2$$
9. Find the vertex coordinates:
Vertex is at $$(h, k) = (-2, -4)$$
10. Find the y-intercept:
Set $$x=0$$:
$$y = -\frac{3}{2}(0+2)^2 - 4 = -\frac{3}{2} \times 4 - 4 = -6 - 4 = -10$$
Y-intercept:
$$(0, -10)$$
11. Express function in standard form $$y = ax^2 + bx + c$$:
Expand the vertex form:
$$y = -\frac{3}{2}(x+2)^2 - 4 = -\frac{3}{2}(x^2 + 4x + 4) - 4 = -\frac{3}{2}x^2 - 6x - 6 - 4$$
Simplify:
$$y = -\frac{3}{2}x^2 - 6x - 10$$
12. Calculate the discriminant $$\Delta = b^2 - 4ac$$:
Here, $$a = -\frac{3}{2}, b = -6, c = -10$$
Calculate:
$$\Delta = (-6)^2 - 4 \times \left(-\frac{3}{2}\right) \times (-10) = 36 - 4 \times \frac{3}{2} \times 10 = 36 - 60 = -24$$
Discriminant is negative, meaning no real roots.
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13. Problem statement: Analyze rainfall data for PNG first 90 days.
14. Find the range:
Range = max - min rainfall:
Max = 280 mm, Min = 0 mm
$$\text{Range} = 280 - 0 = 280\,mm$$
15. Number of days with rainfall < 161 mm:
Add days for intervals 0-40, 41-80, 81-120, 121-160:
$$10 + 16 + 25 + 30 = 81\,\text{days}$$
16. Number of days with rainfall between 45 mm and 200 mm:
Include intervals 41-80 (partially), 81-120, 121-160, 161-200 (partially):
From 45 to 200 mm includes 41-80 fully (16 days), 81-120 (25 days), 121-160 (30 days), and part of 161-200 (22 days).
Assuming full intervals are included except 41-80 starts from 45 (>41) and 161-200 ends at 200 (includes all 22 days):
Total:
$$16 + 25 + 30 + 22 = 93\,\text{days}$$ (Note total days exceeds 90; so clarify intervals and adjust by partial)
Since total days are 90, adjust calculations:
- 0-40: 10 days
- 41-80: 16 days
- 81-120: 25 days
- 121-160: 30 days
- 161-200: 22 days
- Sum: 10+16+25+30+22=103 exceeds total 90, likely overlapping counts or data error
Treat all as full intervals; question expects summation of days where rainfall lies between 45 and 200 mm:
Days with rainfall 41-80 =16 (include all), 81-120=25, 121-160=30, 161-200=22
From 45 mm, remove some from 41-80 interval (41-44 mm days unknown), assume entire 16 days included.
So approximate:
$$16 + 25 + 30 + 22 = 93$$ (acknowledge data inconsistency but answer as asked)
17. Most frequent rainfall measurement:
Identify interval with maximum days:
Maximum days = 30 (121-160 mm interval)
18. Days with rainfall > 200 mm:
Sum days in 201-240 and 241-280 intervals:
$$12 + 5 = 17\,\text{days}$$