Question

HELP MEEEE !!
Find the slope of the secant to the curve f(x)=0.75(3)^x -1 between:
x=o and x=1

Answer 1

When x=0, what's the value of f(x)?
When x=1, what's the value of f(x)?

Answer 2

what do you do after you plug in the numbers?

Answer 3

@kc_kennylau

Answer 4

You get two points, (0, ??) and (1, ??).

Answer 5

Then you can calculate the slope using the formula \(\huge m=\dfrac{y_2-y_1}{x_2-x_1}\)

Answer 6

okay so for part b is it the same thing?

Answer 7

Extend the results from part a) to determine the slope of the tangent to the curve at x = 0, accurate to 3 decimal places.

Answer 8

@kc_kennylau

Answer 9

sorry but which grade are you in? :)

Answer 10

12

Answer 11

Do you know calculus?

Answer 12

I dont have it yet

Answer 13

I think this is what the teacher wants you to do (Just I think):
So the tangent is just the secant between x=0 and x=0.000000000000000001

Answer 14

oh ok

Answer 15

ofc you don't need so many 0s

Answer 16

thanks :)

Answer 17

no problem :)

Answer 18

An antique vase was appraised in 2000 for $8000. If the vase appreciates in value by 6% per year, what is its estimated value in the year 2040, to the nearest thousand dollars?

Answer 19

@kc_kennylau

Answer 20

\[\huge F=I(1+r\%)^t\]
A=Final value
P=Initial value
r=rate
y=time

Answer 21

what would be the answer then?

Answer 22

\[8000\times(1+6\%)^{40}\]

Answer 23

so the answer is 82285??

Answer 24

@kc_kennylau

Answer 25

The nearest THOUSAND dollars

Answer 26

83000

Answer 27

And if anything it's 82286 not 82285

Answer 28

nope

Answer 29

82000???

Answer 30

exactly

Answer 31

oh thanks!!

Answer 32

The world population doubles approximately every 40 years. If the population was approximately 4.5 billion in 1980, what is the projected approximate population in the year 2080? @kc_kennylau

Answer 33

How many years are there between 1980 and 2080?

Answer 34

100

Answer 35

@kc_kennylau

Answer 36

How many years is a period?

Answer 37

12??

Answer 38

idk

Answer 39

40

Answer 40

ohhh

Answer 41

How many periods are there?

Answer 42

40

Answer 43

100

Answer 44

40 years=1 period, 100 years=? periods

Answer 45

2 and something

Answer 46

2.5

Answer 47

so can you put it into the equation for me ?

Answer 48

Now plug all the values into the formula:
\[\huge F=I(1+r\%)^p\]
F=Final value (The number of ppl in 2080)
I=Initial value (The number of ppl in 1980)
r=Rate (By how many percent does it increase in one period?)
p=number of Periods (How many periods are there?)

Answer 49

what is r?

Answer 50

100

Answer 51

Since doubling means increasing by 100%

Answer 52

answer is 461334.5??

Answer 53

@kc_kennylau

Answer 54

nope, how did you get this value?

Answer 55

by plugging in the numbers

Answer 56

4.5(1+100%)^2.5 ???

Answer 57

@kc_kennylau

Answer 58

yep

Answer 59

thats what I got :(
what did you get ???

Answer 60

https://www.google.com.hk/search?q=4.5(1%2B100%25)%5E2.5&oq=4.5(1%2B100%25)%5E2.5&aqs=chrome..69i57j0.1475j0j7&sourceid=chrome&espv=210&es_sm=93&ie=UTF-8

Answer 61

I got 25 billion...

Answer 62

ohhh I see what I did wrong

Answer 63

so you get it now? :)

Answer 64

Inflation is causing a rise of approximately 2% per year in the cost of living.

A bag of milk costs $3.95 now. Estimate the cost five years from now.
A movie ticket costs approximately $11.00 now. If inflation continues at 2% per year, when will the ticket cost $13.50?
If the move ticket costs approximately $11.00 now, how long ago did it cost $4.00?

Answer 65

Inflation is causing a rise of approximately 2% per year in the cost of living. (6 marks)
a.A bag of milk costs $3.95 now. Estimate the cost five years from now.
b. A movie ticket costs approximately $11.00 now. If inflation continues at 2% per year, when will the ticket cost $13.50?
c. if the move ticket costs approximately $11.00 now, how long ago did it cost $4.00?

Answer 66

Can you try to do it yourself first? :)

Answer 67

same equation right?

Answer 68

of course :)

Answer 69

but Im confused :( I suck at this

Answer 70

can you put it in the equation and then I can solve it ...

Answer 71

For part a:
1. What are you trying to find, i.e. the unknown?
2. What values are given?
3. Can you put it in the equation?
4. Can you solve the equation?

For part b:
1. What are you trying to find, i.e. the unknown?
2. What values are given?
3. Can you put it in the equation?
4. Can you solve the equation?

For part C:
1. What are you trying to find, i.e. the unknown?
2. What values are given?
3. Can you put it in the equation?
4. Can you solve the equation?


Sorry, I cannot just do it for you, since I discover that this method cannot help you learn. Just doing the homework for others may be able to help some people, but not all people.

Answer 72

@kc_kennylau for a I got 22

Answer 73

is t right ??

Answer 74

nope :/

Answer 75

I plugged it into the equation :(

Answer 76

can you show me how you plugged? :)

Answer 77

3.95(1+100)^2.5

Answer 78

the rate is not 100% this time, and the number of periods ain't 2.5 this time...

Answer 79

it will be 1

Answer 80

"a rise of approximately 2% per year"
"five years from now"

Answer 81

Sorry give me two minutes, I have to reset my modem :/

Answer 82

hi i'm back :)

Answer 83

hii

Answer 84

so what is r?

Answer 85

@kc_kennylau

Answer 86

2

Answer 87

and the period?

Answer 88

@kc_kennylau

Answer 89

5

Answer 90

4.36

Answer 91

yep

Answer 92

you still can't get the answer by yourself... what do you not understand? :)

Answer 93

idk just the period

Answer 94

for part b we're solving p ?

Answer 95

yep

Answer 96

so the period is the thing after "per", like if it says "per year", the period is 1 year.
and the number of period is the number of years divided by the length of one period. For example, if the question asks for 5 years, the number of period is 5.

Answer 97

so what is the p for part b?