上Fourier变换的性质
- 对偶性质:
![<\mathcal{F}[f],\varphi>=<f,\mathcal{F}[\varphi]>](http://ericcong.com/wp-content/cache/tex_3f1acfdb428e575bdea8e98956df03f6.png)
- 微分性质:
=ixi \mathcal{F}[f](xi)](http://ericcong.com/wp-content/cache/tex_cdd89cf49d2124c5b5350de4f5a5f71d.png)
- 微分性质:
![(\mathcal{F}[f])'(xi)=\mathcal{F}[-ixf(x)](xi)](http://ericcong.com/wp-content/cache/tex_301fe985acfab19f54ac259b7f24e1a0.png)
上Fourier逆变换的性质
- 对偶性质:
![<\mathcal{F}^{-1}[f],\varphi>=<f,\mathcal{F}^{-1}[\varphi]>](http://ericcong.com/wp-content/cache/tex_edafc0acc14eca0546962b86d1e58211.png)
- 微分性质:
=-ix \mathcal{F}^{-1}[f](x)](http://ericcong.com/wp-content/cache/tex_ee2367281c5a8e77104a303984ee27da.png)
- 微分性质:
![(\mathcal{F}^{-1}[f])'(x)=\mathcal{F}^{-1}[-i xi f(xi)](x)](http://ericcong.com/wp-content/cache/tex_55553f0a91e7e64de282b35c8fb38881.png)
上Fourier变换的性质
- 微分性质:
=i xi \mathcal{F}[\varphi](xi)](http://ericcong.com/wp-content/cache/tex_d690c002d42acf9509bfab79b25bdea5.png)
- 微分性质:
![(\mathcal{F}[\varphi])'(xi)=\mathcal{F}[-ix \varphi (x)](xi)](http://ericcong.com/wp-content/cache/tex_947a60b3f91c3aad6a59a1454cbe7f21.png)
- 平移性质:
=e^{-ia xi}\mathcal{F}[\varphi](xi)](http://ericcong.com/wp-content/cache/tex_814448db152e8503bf3d92a22cd157fe.png)
- 伸缩性质:
=\frac{1}{|b|}\mathcal{F}[\varphi](frac{xi}{b})](http://ericcong.com/wp-content/cache/tex_5982173838a88c015fa846f13013cf2c.png)
- 卷积性质:
![\mathcal{F}[\varphi_1 * \varphi_2]=\mathcal{F}[\varphi_1]\mathcal{F}[\varphi_2]](http://ericcong.com/wp-content/cache/tex_39dfd5bcbe4c5678bafe52528c242c41.png)
- 卷积性质:
![\mathcal{F}[\varphi_1 \varphi_2]=\frac{1}{2 pi} \mathcal{F}[\varphi_1]* \mathcal{F}[\varphi_2]](http://ericcong.com/wp-content/cache/tex_1bb52b374454834f81aa708ea0be9062.png)
上Fourier逆变换的性质
- 微分性质:
=-ix \mathcal{F}^{-1}[\varphi](x)](http://ericcong.com/wp-content/cache/tex_a77c858d8690eb7edbf04ee165d9dc61.png)
- 微分性质:
![(\mathcal{F}^{-1}[\varphi])'(x)=\mathcal{F}^{-1}[-i xi \varphi (xi)](x)](http://ericcong.com/wp-content/cache/tex_3cb5e9a4dac1cf128ca458fb36355bfb.png)
- 平移性质:
=e^{-iax}\mathcal{F}[\varphi](x)](http://ericcong.com/wp-content/cache/tex_eca18284c40410706fb2ecdfc99ce42f.png)
- 伸缩性质:
=\frac{1}{|b|}\mathcal{F}^{-1}[\varphi](frac{x}{b})](http://ericcong.com/wp-content/cache/tex_57a2f05ff20b4e5de0262ba91a968eb8.png)
- 卷积性质:
![\mathcal{F}^{-1}[\varphi_1 * \varphi_2]=2 pi \mathcal{F}^{-1}[\varphi_1]\mathcal{F}^{-1}[\varphi_2]](http://ericcong.com/wp-content/cache/tex_9c69558d79039dd72dc4d4fc3a2f2d4b.png)
- 卷积性质:
![\mathcal{F}^{-1}[\varphi_1 \varphi_2]=\mathcal{F}^{-1}[\varphi_1]* \mathcal{F}^{-1}[\varphi_2]](http://ericcong.com/wp-content/cache/tex_7f75ad8ed3a6d6975b86e9e566987384.png)
上Fourier变换的性质![<\mathcal{F}[f],\varphi>=<f,\mathcal{F}[\varphi]>](http://ericcong.com/wp-content/cache/tex_3f1acfdb428e575bdea8e98956df03f6.png)
=ixi \mathcal{F}[f](xi)](http://ericcong.com/wp-content/cache/tex_cdd89cf49d2124c5b5350de4f5a5f71d.png)
![(\mathcal{F}[f])'(xi)=\mathcal{F}[-ixf(x)](xi)](http://ericcong.com/wp-content/cache/tex_301fe985acfab19f54ac259b7f24e1a0.png)
上Fourier逆变换的性质![<\mathcal{F}^{-1}[f],\varphi>=<f,\mathcal{F}^{-1}[\varphi]>](http://ericcong.com/wp-content/cache/tex_edafc0acc14eca0546962b86d1e58211.png)
=-ix \mathcal{F}^{-1}[f](x)](http://ericcong.com/wp-content/cache/tex_ee2367281c5a8e77104a303984ee27da.png)
![(\mathcal{F}^{-1}[f])'(x)=\mathcal{F}^{-1}[-i xi f(xi)](x)](http://ericcong.com/wp-content/cache/tex_55553f0a91e7e64de282b35c8fb38881.png)
上Fourier变换的性质=i xi \mathcal{F}[\varphi](xi)](http://ericcong.com/wp-content/cache/tex_d690c002d42acf9509bfab79b25bdea5.png)
![(\mathcal{F}[\varphi])'(xi)=\mathcal{F}[-ix \varphi (x)](xi)](http://ericcong.com/wp-content/cache/tex_947a60b3f91c3aad6a59a1454cbe7f21.png)
=e^{-ia xi}\mathcal{F}[\varphi](xi)](http://ericcong.com/wp-content/cache/tex_814448db152e8503bf3d92a22cd157fe.png)
=\frac{1}{|b|}\mathcal{F}[\varphi](frac{xi}{b})](http://ericcong.com/wp-content/cache/tex_5982173838a88c015fa846f13013cf2c.png)
![\mathcal{F}[\varphi_1 * \varphi_2]=\mathcal{F}[\varphi_1]\mathcal{F}[\varphi_2]](http://ericcong.com/wp-content/cache/tex_39dfd5bcbe4c5678bafe52528c242c41.png)
![\mathcal{F}[\varphi_1 \varphi_2]=\frac{1}{2 pi} \mathcal{F}[\varphi_1]* \mathcal{F}[\varphi_2]](http://ericcong.com/wp-content/cache/tex_1bb52b374454834f81aa708ea0be9062.png)
上Fourier逆变换的性质=-ix \mathcal{F}^{-1}[\varphi](x)](http://ericcong.com/wp-content/cache/tex_a77c858d8690eb7edbf04ee165d9dc61.png)
![(\mathcal{F}^{-1}[\varphi])'(x)=\mathcal{F}^{-1}[-i xi \varphi (xi)](x)](http://ericcong.com/wp-content/cache/tex_3cb5e9a4dac1cf128ca458fb36355bfb.png)
=e^{-iax}\mathcal{F}[\varphi](x)](http://ericcong.com/wp-content/cache/tex_eca18284c40410706fb2ecdfc99ce42f.png)
=\frac{1}{|b|}\mathcal{F}^{-1}[\varphi](frac{x}{b})](http://ericcong.com/wp-content/cache/tex_57a2f05ff20b4e5de0262ba91a968eb8.png)
![\mathcal{F}^{-1}[\varphi_1 * \varphi_2]=2 pi \mathcal{F}^{-1}[\varphi_1]\mathcal{F}^{-1}[\varphi_2]](http://ericcong.com/wp-content/cache/tex_9c69558d79039dd72dc4d4fc3a2f2d4b.png)
![\mathcal{F}^{-1}[\varphi_1 \varphi_2]=\mathcal{F}^{-1}[\varphi_1]* \mathcal{F}^{-1}[\varphi_2]](http://ericcong.com/wp-content/cache/tex_7f75ad8ed3a6d6975b86e9e566987384.png)
我他妈把伸缩性质记错了,傻逼了,大傻逼了……