Answer:
Step-by-step explanation:
Hello, please consider the following.
So this is divisible by 3.
Now, to prove that this is divisible by 9 = 3*3 we need to prove that
is divisible by 3. We will prove it by induction.
Step 1 - for n = 1
4+17=21= 3*7 this is true
Step 2 - we assume this is true for k so 
is divisible by 3
and we check what happens for k+1
is divisible by 3 and
is divisible by 3, by induction hypothesis
So, the sum is divisible by 3.
Step 3 - Conclusion
We just prove that is divisible by 3 for all positive integers n.
Thanks
Answer:
slope is 0
Step-by-step explanation:
Answer:
a. 80.83 ft b. 40.42 ft
Step-by-step explanation:
Let h = height of pole = 70 ft, L = length of cable and x = distance of cable on ground to pole and Ф = angle between cable and ground.
a) How long is the cable?
Since L, h and x form a right-angled triangle with angle Ф and h being the opposite side to Ф and L being the hypotenuse side, by trigonometric ratios,
sinФ = h/L
L = h/sinФ
L = 70 ft/sin60°
L = 70 ft/0.8660
L = 80.83 ft
b) How far from the pole should the cable be attached to the ground?
Since L, h and x form a right-angled triangle with angle Ф and h being the opposite side to Ф and x being the adjacent side, by trigonometric ratios,
tanФ = h/x
x = h/tanФ
x = 70 ft/tan60°
x = 70 ft/1.7321
x = 40.42 ft
The area of the screw head is 93.5m².
<h3>How to calculate the area?</h3>
The area of the hexagon can be illustrated based on the formula:
A = 3✓3/2 × a²
Base = 12.
Height = 3.
Area of each triangle = 0.5 × 12 × 3 = 18
Area of the rectangle = 12 × 6 = 72
Therefore the area of the screw head will be:
= 3√3/2 × 72
= 93.5m²
Learn more about area on:
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