Question

How do you write a rule for the nth term of the arithmetic sequence given d=1/2, `a_5=20`?

Answer 1

`a_n=1/2n+35/2`

Explanation:

`"the n th term of an arithmetic sequence is"`

`•color(white)(x)a_n=a_1+(n-1)d`

`"we require to find "a_1`

`a_5=a_1+(4xx1/2)=20rArra_1=18`

`a_n=18+1/2(n-1)`

`color(white)(a_n)=18+1/2n-1/2`

`color(white)(a_n)=1/2n+35/2larrcolor(red)" n th term formula"`