3.2.1 Algebra and Functions (A-level only)

A scientist models the intensity gain $G\,$ of a signal passing through a specialized fiber-optic cable as a function of the input power $x$ :

\frac{2 + \sqrt{28x}}{3 + \sqrt{7x}}, \quad x > 0, x \neq \frac{9}{7}

Show that $G\,$ can be written in the form:

\frac{14x - 6 - 4\sqrt{7x}}{7x - 9}

[5]

A scientist models the intensity gain $G\,$ of a signal passing through a specialized fiber-optic cable as a function of the input power $x$ :

\frac{2 + \sqrt{28x}}{3 + \sqrt{7x}}, \quad x > 0, x \neq \frac{9}{7}

Show that $G\,$ can be written in the form:

\frac{14x - 6 - 4\sqrt{7x}}{7x - 9}

[5]

3.2.1 Algebra and Functions (A-level only) Questions