Pixel:

http://prntscr.com/hd4v0u

1 year ago
Pixel:

@sammixboo

1 year ago
Pixel:

1 year ago
Pixel:

is it +10 +11 +12+13+14+15 etc.

1 year ago
Pixel:

@dude

1 year ago

Do you know how to write an exponential function?

1 year ago
Pixel:

no

1 year ago

The form looks like this: $f(x) = ab ^{x}$ Where a is our starting value, and b is our common ratio between our y values. Our starting value is the number in the set of y values that corresponds with x at zero. Can you identify the starting value?

1 year ago
Pixel:

100?

1 year ago

Correct.

1 year ago

Now as for our common ratio, there is a simple way to discover it. Simple look at our y values. We have 100, 110, and 121. Use this formula. $b = \frac{ y _{2} }{ y _{1}}$ Remember that b is our common ratio between our y values. You can solve for this by dividing any number in the our set of y values, by the number that came before it. This gives us the number by which you multiply, to get the next number.

1 year ago
Pixel:

so 110 / 100?

1 year ago

Does that make sense?

1 year ago

Correct

1 year ago
Pixel:

1.1

1 year ago

You have a and b, can you put the exponential function together now?

1 year ago
Pixel:

f(x)=100 x 1.1?

1 year ago

Close $f(x) = 100(\frac{ 11 }{ 10 })^{x}$ or $f(x) = 100(1.1)^{x}$ Some teachers may prefer it in fraction form.

1 year ago
Pixel:

is the x the year ?

1 year ago

Now that we have our exponential function, try input any x value (years) into our x, and solve for an output (which would give us the number of trucks registered in a year).

1 year ago
Pixel:

ok

1 year ago
Pixel:

990? if it is 9 years

1 year ago

Remember that we are taking it to the power of x, not multiplying it by x.

1 year ago

$1^3 = 1 \times 1 \times 1 \neq 1 \times 3$

1 year ago
Pixel:

oops XD

1 year ago
Pixel:

235.794769

1 year ago