The sum of the first n odd numbers is n squared! So, the short answer is that the sum of the first 70 odd numbers is 70 squared, i.e. 4900.
Allow me to prove the result: odd numbers come in the form 2n-1, because 2n is always even, and the number immediately before an even number is always odd.
So, if we sum the first N odd numbers, we have
The first sum is the sum of all integers from 1 to N, which is N(N+1)/2. We want twice this sum, so we have
The second sum is simply the sum of N ones:
So, the final result is
which ends the proof.
Answer:
14 feet.
Step-by-step explanation:
Use the tangent function:
a = length of antenna:
a = 14.09538931 ≈ 14
The minimum score was 70.
On a box-and-whisker, the dot on the left end is the lowest value.
The first line on the left is the lower quartile.
The second line is the median.
The third line is the upper quartile.
And finally, the dot on right end is the highest value.
Hope I could help :)
Answer: It represents the area of the two circular sides ("lids")
Explanation:
Imagine you made a cylinder out of 3 pieces of paper. The cylinder can be decomposed into two circular shapes (radius r) and one rectangular piece with two side lengths: one is "h", the other has to be long enough to go around each of the disks, so it has to be 2*pi*r long.
So the term 2*pi*r*h is the area of the rectangular piece and pi*r^2 is the area of each of the "lids" Since there are two of those, the term 2*pi*r^2 represents the area of the bottom and top lids.
Step-by-step explanation:
12. Cos 60° = 8/c
0,5 = 8/c
0,5 c = 8
c = 16
D² = V16²-8²
= V256-64
=V192 = V16×12 = 4V12
= 4V4×3 = 8V3
13. Cos 30° = 6/b
V3/2 = 6/b
V3 b = 12
b = 12/V3
b/Sin B = a /sin A
b/Sin90° = 6/ sin 60°
<u>b</u> = <u> </u><u> </u><u> </u><u>6</u><u> </u><u> </u><u> </u>
1 V3/2
b× <u>V3</u> = 6
2
b = 6× 2/V3
= 12/V3
