Question

When plucked, the high E string on a guitar has a frequency of 330 cycles per second. What sine function represents this note when it is graphed with an amplitude of 1.5 units? Let x represent the number of seconds.

Answer 1

`\bf \qquad \qquad \qquad \qquad \textit{function transformations} \\ \quad \\ % function transformations for trigonometric functions \begin{array}{rllll} % left side templates f(x)=&{{ A}}sin({{ B}}x+{{ C}})+{{ D}} \\ \quad \\ \end{array}`





`\bf \begin{array}{llll} \bullet \textit{vertical shift by }{{ D}}\\ \qquad if\ {{ D}}\textit{ is negative, downwards}\\ \qquad if\ {{ D}}\textit{ is positive, upwards}\\\\ \bullet \textit{function period or frequency}\\ \qquad \frac{2\pi }{{{ B}}}\ for\ cos(\theta),\ sin(\theta),\ sec(\theta),\ csc(\theta)\\ \qquad \frac{\pi }{{{ B}}}\ for\ tan(\theta),\ cot(\theta) \end{array}`

now.. if the period/frequency is 330, then we know that
`\bf \cfrac{2\pi }{B}=300`

solve for B, and then plug it in the equation
and use the provided amplitude