Find the common difference of the sequence.
-$a _ { 1 } = \frac { 9 } { 2 } , a _ { 4 } = \frac { 21 } { 2 } ; \text { find } \mathrm { d }$
A)2
B) $\frac { 1 } { 2 }$
C)4
D)6

Question

Quizplus · Accepted Answer

The common difference $d$ in an arithmetic sequence can be found using the formula $a_n = a_1 + (n - 1)d$, where $a_n$ is the nth term, $a_1$ is the first term, and $n$ is the term number. Given $a_1 = \frac{9}{2}$ and $a_4 = \frac{21}{2}$, we can substitute these values into the formula for $n = 4$: $\frac{21}{2} = \frac{9}{2} + (4 - 1)d$. Solving for $d$, we find $d = 4$.

Find the Common Difference of the Sequence a1=92,a4=212; find da _ { 1 } = \frac { 9 } { 2 } , a _ { 4 } = \frac { 21 } { 2 } ; \text { find } \mathrm { d }a1​=29​,a4​=221​; find d

Find the Common Difference of the Sequence $a _ { 1 } = \frac { 9 } { 2 } , a _ { 4 } = \frac { 21 } { 2 } ; \text { find } \mathrm { d }$