Answer:
2n² + n
Step-by-step explanation:
<u>Given sequence</u>:
3, 10, 21, 36, ...
Work out the first differences between terms:
As the <u>first differences</u> are <em>not </em>the same, work out the second differences.
As the second differences are the <u>same</u>, the sequence is quadratic and will contain an n² term.
The coefficient of n² is always <u>half of the second difference</u>. Therefore, as the second difference is 4, the coefficient of n² is 2.
To work out the nth term of the sequence, write out the numbers in the sequence 2n² and compare with the given sequence:
Therefore, we need to add n to 2n² to match the sequence.
Therefore, the nth term of this sequence is 2n² + n.
Learn more about sequences here:
brainly.com/question/27953040
brainly.com/question/27775450