Question

Need help with pre-cal expansion. Look in comments for equation.

Answer 1

Expand \[\sum_{k=1}^{4}(k-1)(k-2)\]

Answer 2

I got (1-1)(1-2) +(2-1)(2-2) + (3-1)(3-2) +(4-1)(4-2). Is this right?

Answer 3

correct

Answer 4

Thanks!

Answer 5

How about this one: Write 1, 4, 9, 16, 25, 36 in sigma notation.

Answer 6

Is it \[\sum_{k=1}^{7}k^2\]

Answer 7

That's what I got. But I am not sure about the 7. I had\[\sum_{k=1}^{6}k^2\] But I may be wrong. The second part is correct though

Answer 8

Yeah, it's 6. Counted wrong.

Answer 9

Okay, next is find the sigma notation for -3, -2, -1, 0, 1.

Answer 10

Is it \[\sum_{k=-4}^{5}k+1\]

Answer 11

The top number is 0 since you started at -4

Answer 12

Ah, makes sense

Answer 13

So \[\sum_{k=-4}^{0}k+1\]

Answer 14

yep

Answer 15

Awesome, thanks

Answer 16

np