Question

.Consider circles, points on its circumference
and chords as shown in the figure. Mark two
points on the circle and draw a chord. Mark
one more point and draw three chords.
Continue this process by adding one more
point each time.
Question pool
a) Write the number of chords in each figure as a
sequence.
b) Write the algebraic expression of this sequence
c) Find the number of chords in the 10th figure?​

Answer 1

Answer:

this is a circle and a cord

Answer 2

Answer:

a)1st term=1

2nd term=3

3rd term=6

4th term=10

b)nth term=1+2+3+...+n

=n(n+1)/2

c)10th term=10x11/2=5x11=55

Step-by-step explanation:If you look closely,this sequence follows in such a way that the term are the sum of the consecutive natural numbers. For eg. If you have to find the 2nd term, then the answer is the sum of the first two natural numbers, i.e. 2nd term=1+2=3.

Same goes for any term, for eg. 9th term=1+2+3+4+5+6+7+8+9=9x10/2=9x5=45

Hope my answer was helpful!