diff options
| -rw-r--r-- | Fourier Series.page | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/Fourier Series.page b/Fourier Series.page index 91bad7a..3ede531 100644 --- a/Fourier Series.page +++ b/Fourier Series.page @@ -15,7 +15,7 @@ Rearranging, $\qquad\sin^2(x) = \frac{1-\cos(2x)}{2}$ -$2.\quad\sin(2x).\cos(2x) = ?$ +$2.\quad\sin(2x)\cdot\cos(2x) = ?$ Based on the double angle formula, @@ -23,7 +23,7 @@ $\qquad\sin(2x) = 2\sin(x)\cos(x)$ Rearranging, $$\begin{array}{ccl} -\sin(2x).\cos(x) & = & [2\sin(x)\cos(x)].\cos(x)\\ +\sin(2x)\cdot\cos(x) & = & [2\sin(x)\cos(x)]\cdot\cos(x)\\ & = & 2 \sin(x) [ 1 - \sin^2(x)]\\ & = & 2\sin(x) - 2\sin^3(x)\\ \end{array}$$ @@ -53,6 +53,7 @@ $$ e^{i\theta} & = & \cos \theta + i \sin \theta\\ \end{array} $$ + ##What is the Fourier series actually?</b> ##Why is Fourier series useful? </b> |