Maths - Superposition of Sine and Cos


Flashcards

2021-12-05

In what form can you express $a\sin x \pm b\cos x$?


\[R\sin(x \pm \alpha)\]

In what form can you express $a\cos x \pm b\sin x$?


\[R\cos(x \mp \alpha)\]
You want to express
\[a\sin x \pm b\cos x\]

as

\[R\sin(x \pm \alpha)\]

How can you calculate $R$??

\[R = \sqrt{a^2 + b^2}\]
You want to express
\[a\sin x \pm b\cos x\]

as

\[R\sin(x \pm \alpha)\]

How can you calculate $\alpha$??

\[\tan \alpha = \frac{b}{a}\]
You want to express
\[a\cos x \pm b\sin x\]

as

\[R\cos(x \mp \alpha)\]

How can you calculate $R$??

\[R = \sqrt{a^2 + b^2}\]
You want to express
\[a\cos x \pm b\sin x\]

as

\[R\cos(x \mp \alpha)\]

How can you calculate $\alpha$??

\[\tan \alpha = \frac{b}{a}\]



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