update day3 homework

Author: alvinhuu

D03/homework.py

@@ -0,0 +1,19 @@
+import numpy as np
+
+V1 = 20000
+V0 = 20
+
+def db2V1(db):
+    return np.power(10,db/20)*V0
+
+gdb = 20*np.log10(V1/V0)
+print('正常的談話的聲壓為 20000 微巴斯卡，請問多少分貝: answer is %d db' % gdb)
+
+V30db = db2V1(30)
+V50db = db2V1(50)
+
+print('30db\'s V1 is %d' % V30db)
+print('50db\'s V1 is %d' % V50db)
+
+print('30 分貝的聲壓會是 50 分貝的幾倍 = {:.3f}'.format(V30db/V50db) )
+