import numpy as np import matplotlib.pyplot as plt def descartes(ax, ran_x, ran_y, ax_title,x_label = "x", y_label = "y"): ax.set_xlabel(x_label, fontsize = 12) ax.set_ylabel(y_label, fontsize = 12) ax.set_xlim(ran_x[0], ran_x[1]) ax.set_ylim(ran_y[0], ran_y[1]) ax.set_title(ax_title, fontsize = 14) ax.grid() ax.axhline(0, color = "black") ax.axvline(0, color = "black") fig = plt.figure(figsize = (6, 6)) ax = fig.add_subplot(111) title1 = "Tokyo University 2024 Math qu.4 NO1" descartes(ax, [-10,10], [-10, 10],title1) cmap = plt.get_cmap('jet') cr=0/30 x=np.linspace(-10,10,1000) y=-1*np.sqrt(2)/4*(x**2)+4*np.sqrt(2) ax.plot(x ,y , color = cmap(cr)) for t in range(1,4): #for t in np.linspace(1,4,75): cr=(8+2*t)/50 x1=t y1=-1*np.sqrt(2)/4*(t**2)+4*np.sqrt(2) m=np.sqrt(2)/t x=np.linspace(-10,10,1000) y=m*(x-x1)+y1 ax.plot(x,y,color=cmap(cr)) cr=(20+2*t)/50 m=t/(-1*np.sqrt(2)) x=np.linspace(-10,10,1000) y=m*(x-x1)+y1 ax.plot(x,y,color=cmap(cr)) cr=(42+2*t)/50 theta=np.linspace(0,2*np.pi,100) r=1/4*np.sqrt(t**2+2)*(t**2-16) x2=1/4*(t**3)-3*t y2=0 x=r*np.cos(theta)+x2 y=r*np.sin(theta)+y2 ax.plot(x ,y , color = cmap(cr)) x=x1 y=y1 ax.scatter(x,y,color="red") plt.show()