Hi all, I thought I was beginning to understand AP's but this problem has got me beat. if you are given only the first term u_{1} and then that u_{n} = u_{n+1} - some number, how do you find the first 5 terms?
Hi all, I thought I was beginning to understand AP's but this problem has got me beat. if you are given only the first term u_{1} and then that u_{n} = u_{n+1} - some number, how do you find the first 5 terms?
Please check if you have copied the question correctly. As I understand you are given the first term. Let first term = a
n th trm = (n+2)th term - k ( suppose) Then it is quite simple and you get
a + ( n-1) d = a + nd - k That gives d, common difference d = k Now you can work out the solution
No, look at the pattern:
$\displaystyle u_1=u_1+0\cdot d=u_1+(1-1)d$
$\displaystyle u_2=u_1+1\cdot d=u_1+(2-1)d$
$\displaystyle u_3=u_1+2\cdot d=u_1+(3-1)d$
Do you see the pattern that will continue? Can you state what the general term $\displaystyle u_n$ is?
Ok so have I done this right? I was given that u_{1} = 5 and u_{n}+1 = un-2.3 and asked to find the first 5 terms, so I used the formula u_{n} = a+(n-1)d. I took a = 5 and d = -2.3 and here is what I came up with;
u_{1} = 5 + (1-1)-2.3 = 2.7
u_{2} = 5+ (2-1)-2.3 = 2.7
u_{3} = 5+ (3-1)-2.3 = 0.4
u_{4} = 5+ (4-1)-2.3 = -1.9
u_{5} = 5+(4-1)-2.3 = -4.2
The difference is -2.3 in the last 4, so I assume I am correct? But u1 and u2 should not have the same value?