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Algebra, STD1 EQ-Bank 27

A conservation program is tracking the recovery of a native wildflower species in a national park. At the start of the program there are 200 plants. The number of plants is predicted to grow at a rate of 25% per year.

Let  \(N\) = number of plants, and  \(t\) = time in years.

  1. Complete the table of values below that models the growth of the plants. Round all answers to the nearest whole number.   (2 marks)
    \begin{array}{|c|c|c|c|c|c|}
    \hline
    \rule{0pt}{2.5ex}\quad t \quad \rule[-1ex]{0pt}{0pt}& \quad 0 \quad & \quad 1 \quad& \quad 2 \quad & \quad 3 \quad & \quad 4 \quad \\
    \hline
    \rule{0pt}{2.5ex}N \rule[-1ex]{0pt}{0pt}& 200 & & & & \\
    \hline
    \end{array}

    --- 3 WORK AREA LINES (style=lined) ---

  2. Using the table of values from (a), neatly plot the points and join with a smooth curve.   (2 marks)

    --- 0 WORK AREA LINES (style=lined) ---

      

Show Answers Only

a.    \(\text{Table of values:}\)

\begin{array}{|c|c|c|c|c|c|}
\hline
\rule{0pt}{2.5ex}\quad t \quad \rule[-1ex]{0pt}{0pt}& \quad 0 \quad & \quad 1 \quad& \quad 2 \quad & \quad 3 \quad & \quad 4 \quad \\
\hline
\rule{0pt}{2.5ex}N \rule[-1ex]{0pt}{0pt}& 200 & & & & \\
\hline
\end{array}

b.     

Show Worked Solution

a.    \(\text{Table of values:}\)

\begin{array}{|c|c|c|c|c|c|}
\hline
\rule{0pt}{2.5ex}\quad t \quad \rule[-1ex]{0pt}{0pt}& \quad 0 \quad & \quad 1 \quad& \quad 2 \quad & \quad 3 \quad & \quad 4 \quad \\
\hline
\rule{0pt}{2.5ex}N \rule[-1ex]{0pt}{0pt}& 200 & & & & \\
\hline
\end{array}

\(\text{Algebraic method}\)

\(\text{Formula:   }\ N=200\times1.25^t\)

\(t=0:\ N=200\times1.25^{0}=200\)

\(t=1:\ N=200\times1.25^{1}=250\)

\(t=2:\ N=200\times1.25^{2}=312.5\approx313\)

\(t=3:\ N=200\times1.25^{3}=390.625\approx391\)

\(t=4:\ N=200\times1.25^{4}=488.28\ldots\approx488\)
  

\(\text{Using CASIO calculator with constant multiplier}\)

\begin{array} {|c|c|c|c|}
\hline t & \text{Input} & \text{Output}\ (N) & \text{Rounded}\ (N) \\
\hline \colorbox{lightblue}{0} & 200= & 200 & \colorbox{lightblue}{200} \\
\hline \colorbox{lightblue}{1} & \text{Ans}\times 1.25= & 250  & \colorbox{lightblue}{250} \\
\hline \colorbox{lightblue}{2} & = & 312.5 & \colorbox{lightblue}{313} \\
\hline \colorbox{lightblue}{3} & = & 390.625 & \colorbox{lightblue}{391} \\
\hline \colorbox{lightblue}{4} & = & 488.28\ldots & \colorbox{lightblue}{488} \\
\hline \end{array}  

b.     

   

Filed Under: Graphs of Practical Situations Tagged With: Band 4, Band 5, smc-6840-10-Non-linear Graphs

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