questions on attachment!!!!

- Jul 26th 2006, 06:56 PMLane10 questions that I need HELP ON!!! Please i can't do them!!!
questions on attachment!!!!

- Jul 26th 2006, 08:23 PMThePerfectHackerQuote:

Use sigma notation to write the sum. -2.4-.4+1.6+3.6

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Find a formula for an for the arithmetic sequence. a1=7, a11=19

Substitute know values,

Thus,

Thus,

"An arithemtica sequnce with initial term of 7 and constant diffrence of 1.2"

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Find a formula for an for the arithmetic sequence. a1=11, a11=15

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A rubber ball on a hard surface takes a sequence of vertical bounces. Each bounce is 1/6 as high as the proceeding one. If this ball is dropped from a height of 12 feet, find the total distance it has traveled when it hits the surface the fifth time.

Thus,

---> Because you only got 5 bounces (do not think the exponent is 4 :eek: a common mistake it should be 4)

Thus, factor

Use sum for geometric series,

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6. Write the first five terms of the sequence.

a0=-2

a1=4

an=-2a n -1-4an-2

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7. Find the coefficient of b6a2 in the expansion of (b+2a)8

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8. Use the binomial theorem to expand and simplify the expression.

(s-u)5

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9. A college has seven instructors qualified to teach a special computer lab course which requires two instructors to be present. How many different pairs of teachers could teach the class.

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10. Eight cards are drawn, without replacement, from a standard deck of 52 cards. How many sets of eight cards are possible?

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11.

- Jul 27th 2006, 05:48 AMSoroban
Hello, Lane!

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Use sigma notation to write the sum:

Here are two possible sigma-representations.

It starts with ... and 2 is added three times: .

It starts with and 2 is added four times: .

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2. Find a formula for for the arithemtic sequence:

Recall the formula for the term: .

. . where is the first term and is the common difference.

We are given , so the formula becomes: .

We are given ... the term is

So we have: .

Therefore: .

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5. A rubber ball on a hard surface takes a sequence of vertical bounces.

Each bounce is 1/6 as high as the preceeding one.

If the ball is dropped from a height of 12 feet,

find the total distance it has traveled when it hits the surface for the fifth time.

**Warning**: "The Bouncing Ball" is a classic*trick question.*

I'll baby-step through the explanation . . .

The ball falls feet. .(Contact #1)

It bounces up . feet . . . and falls . feet. .(Contact #2)

It bounces up feet . . . and falls feet. .(Contact #3)

. . You get the idea . . .

By the 5th contact, the total distance is:

. .

. .

- Jul 27th 2006, 06:50 AMSoroban
Hello again, Lane!

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7) Find the coefficient of in the expansion of

The expansion begins: .

The third term is: .

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8. Use the binomial theorem to expand and simplify:

If you don't know the Binomial Theorem, we can't be much help.

. . I expanded it . . .can simplify it.*you*