zad1
import numpy as np
import matplotlib.pylab as plt

def wartosc(f,x=0):
    return eval(f,{'x':x})

wielomian = 'x**2+3*x*(-1/27)+0.2'
x=np.array([1,2,3])
y=np.array([1,3,8])
z=y+0
for i in range(0,len(x)):
    z[i]=wartosc(wielomian,x[i])

plt.plot(x,y, "ro", ms=10)
plt.plot(x,z,lw=2)
plt.xlim(0,4)
plt.show()

zad2
import numpy as np
from scipy import signal
import matplotlib.pyplot as plt

t=np.linspace(0,4,1000, endpoint=False)
tp=signal.square(np.pi*t)

ts=1.28*(np.sin(np.pi*t)+(1/3)*np.sin(np.pi*3*t)+(1/5)*np.sin(np.pi*5*t)+(1/7)*np.sin(np.pi*7*t)+(1/9)*np.sin(np.pi*9*t)+(1/11)*np.sin(np.pi*11*t)+(1/13)*np.sin(np.pi*13*t)+(1/15)*np.sin(np.pi*15*t)+(1/17)*np.sin(np.pi*17*t)+(1/19)*np.sin(np.pi*19*t)+(1/21)*np.sin(np.pi*21*t))

plt.plot(t,tp)
plt.plot(t,ts)
plt.show()