Pixel:

http://prntscr.com/hd4v0u

7 months ago
Pixel:

@sammixboo

7 months ago
Pixel:

@Shadow

7 months ago
Pixel:

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

7 months ago
Pixel:

@dude

7 months ago
Shadow:

Do you know how to write an exponential function?

7 months ago
Pixel:

no

7 months ago
Shadow:

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?

7 months ago
Pixel:

100?

7 months ago
Shadow:

Correct.

7 months ago
Shadow:

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.

7 months ago
Pixel:

so 110 / 100?

7 months ago
Shadow:

Does that make sense?

7 months ago
Shadow:

Correct

7 months ago
Pixel:

1.1

7 months ago
Shadow:

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

7 months ago
Pixel:

f(x)=100 x 1.1?

7 months ago
Shadow:

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

7 months ago
Pixel:

is the x the year ?

7 months ago
Shadow:

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).

7 months ago
Pixel:

ok

7 months ago
Pixel:

990? if it is 9 years

7 months ago
Shadow:

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

7 months ago
Shadow:

\[1^3 = 1 \times 1 \times 1 \neq 1 \times 3\]

7 months ago
Pixel:

oops XD

7 months ago
Pixel:

235.794769

7 months ago
Shadow:

Correct :)

7 months ago
Pixel:

236 for rounding

7 months ago