Help??
Find an explicit rule for the nth term of a geometric sequence where the second and fifth terms are -12 and 768, respectively.
Is the answer 3*(-4)^n-1?

Question

Help?? 
Find an explicit rule for the nth term of a geometric sequence where the second and fifth terms are -12 and 768, respectively.
Is the answer 3*(-4)^n-1?

mathmale · Answer

You'll need to find the following:
1.  General formula for a geometric sequence
2.   First term of this sequence (yours)
3.   Common ratio of this sequence 

think:  How will you approach this?  Hint:  Look up "geometric sequence."