Question

Calculus Area help?

use the properties of summation and
Theorem 4.2 to evaluate the sum.

Answer 1

Theorem 4.2

Answer 2

Question

Answer 3

seems like u get all the summation formula in ur theorem section, u just have to apply them to ur Q....

OK u need two more eqns: Summation (c*i) = c*Summation (i) where c is a constant; and

Summation (f(i) + g(i)) = Summation f(i) + Summation g(i)

Answer 4

But I don't know which I have to apply to that Q. I don't really understand it

Answer 5

First use this to break up the expression in ur Q: (f(i) + g(i)) = Summation f(i) + Summation g(i)

Answer 6

so: (2i +31) = Sim. 2i + Sum. 3(i) ?

Answer 7

The expression inside summation is (2i-3) right?

Answer 8

yes

Answer 9

so using the two eqns i wrote above....u can re-write the prob....

Answer 10

So what I wrote was wrong?

Answer 11

should be Sum. 2i + Sum.3; not i following the constant 3 right?

Answer 12

Oooops should be 2i-3....so plz re-write the eqn....

Answer 13

ah ok so: (2i - 3) = Sum. 2i - Sum 3

Answer 14

Correct! now use Summation (c*i) = c*Summation (i) where c is a constant on the first part....

Answer 15

sum. 2*i = 2 * sum (i)

Answer 16

sum(i) is in ur theorem i believe....

Answer 17

so does sum(i) become 3(3+1) / 2?

Answer 18

where does the 3 come from??

Answer 19

hey sorry I had to go. wouldn't (n) be the constant 3? or no?

Answer 20

n is constant but it is a different constant....not 3. plz read ur theorem n the prob itself again n u will see :)

Answer 21

I did. but there are only two constants...

Answer 22

c and n in the theorem section right?

Answer 23

therom #1 is c and theorem #2 shows n

Answer 24

ok and in this case, what is n? hint: it is not 3 :)

Answer 25

2?

Answer 26

superdave I have to go to sleep will you be around tomorrow to work on this? please?

Answer 27

Sure :) good nite!

Answer 28

thanks so much!!

Answer 29

@ganeshie8 @eliassaab could you guys help me please?

Answer 30

\(\large \sum \limits_{i=1}^{15} (2i -3)\)


\(\large \sum \limits_{i=1}^{15} 2i - \sum \limits_{i=1}^{15} 3\)

\(\large 2 \sum \limits_{i=1}^{15} i - 3 \sum \limits_{i=1}^{15} 1\)

\(\large 2 \frac{15(15+1)}{2} - 3 \times 15\)

Answer 31

simplify

Answer 32

uhm what does large stand for?

Answer 33

oh there must be an issue with latex.
u should not see large and all... let me take a snapshot and attach :)

Answer 34

thank you

Answer 35

^^ attached wat i see from my side

Answer 36

hey sorry ... ok so let me simplify

Answer 37

2 ( 75 + 15 / 2) - 45

Answer 38

2 (90 / 2) - 45

Answer 39

2( 45) - 45

Answer 40

90 - 45 = 45

Answer 41

45

Answer 42

@lovablenene I'm done right?

Answer 43

2* 15(15+1)/2 - 3*15

15(16) - 45

195

Answer 44

http://www.wolframalpha.com/input/?i=sum+i%3D1+to+15++%282i-3%29

Answer 45

Ok I see now. Thank you