To find the value of a57 for the given sequence {an}={-6,-9/2,-3,-3/2,0...}, we can observe that the sequence is decreasing by 3/2 each time.
First term, a1 = -6
Second term, a2 = -9/2 = -4.5
Third term, a3 = -3
Fourth term, a4 = -3/2 = -1.5
We can see that the nth term is given by: an = -6 + (n-1)(-3/2)
To find a57, we substitute n = 57 in the above equation:
a57 = -6 + (57-1)(-3/2)
a57 = -6 + 56(-3/2)
a57 = -6 + (-84)
a57 = -90
Therefore, a57 = -90.
The correct option is not provided in the given choices.
calculate a57 for the sequence {an}={-6,-9/2,-3,-3/2,0...}
a. 78
b. 159/2
c. 81
d. 171/2
2 answers
78