Mathematics 4024 · O Level · Exponential growth and decay

Exponential growth and decay — practice question

(a(i))[1]

Fill in the table for $y = \frac{2^x}{5}$.

(a(ii))[3]

Using the grid, sketch the graph of $y = \frac{2^x}{5}$ for $0 \leq x \leq 5$.

(a(iii))[2]

Show that $\frac{2^x}{5} = \frac{5}{2}$ from the given information.

(a(iv))[2]

Use a line drawn on the grid to solve $2^{x+3} = 100$.

(b)[3]

The sketch shows the graph $y = a + bx - x^2$. It meets the $x$-axis at integer values of $x$. Find the value of $a$ and the value of $b$.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: The value is $6.4$.

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