Use first and second differences to determine whether the sequence
-4,-13,-26,-43,-64... is linear, quadratic, or neither. Note: the first term in the sequence corresponds to $\displaystyle {x}={1}$.

a) The sequence is linearquadraticneither .

b) If the sequence is linear or quadratic, write an equation for the sequence in terms of $\displaystyle {x}$. If "neither", enter XXX.
The equation is $\displaystyle {y}=$ Preview Question 6 Part 2 of 3  

c) If the sequence is linear or quadratic, find the next term in the sequence. If "neither", enter XXX.
The next term is .