Question

if tn=(4n+7), show that the sequence is an arithmetic sequence. find the 1st term.​

Answer 1

Step-by-step explanation:

Tn = 4n + 7, to show that this represents a Arithmetic sequence. and to find the first term a

put n = 1, 2, 3, 4

T1 = 4*1 + 7 = 11

T2 = 4*2 + 7 = 15

T3 = 4*3 + 7 = 19

T4 = 4*4 + 7 = 23

as d = 4 for the entire sequence, it is in

AP

11, 15, 19, 23, ..............

first term a = 11

Answer 2

Answer:

Given that,

Tn=4n+7

So, If Tn+1 -Tn= constant Then sequence will be an AP

Tn+1 =4(n+1)+7=4n+4 +7

Tn+1 =4n+11

Now, d=Tn+1 -Tn =(4n+11)-(4n+7)=4 =Constant

S the given sequence is a an AP with common difference d=4

so the first term of AP will be

a1 = T1=4*1+7=4+7=11