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:
dy/dx = x=-1
Step-by-step explanation:
by use of intergration to get the values of yaxis and x axis,,the values are -2, -4,
Answer:
78
Step-by-step explanation:
Answer:

Step-by-step explanation:
we know that
The area of the figure is equal to the area of rectangle plus the area of two semicircles
<u>The area of rectangle is equal to</u>

<u>The area of the small semicircle is equal to</u>

-----> radius is half the diameter
substitute

<u>The area of the larger semicircle is equal to</u>

-----> radius is half the diameter
substitute

The area of the figure is equal to

What that person say is the file.