clc; 
clear; 
close all; 
f = 70; 
t = 0:0.0001:0.02; 
u = 10*sin(2*pi*f*t); 
du = 20*pi*f*cos(2*pi*f*t); 
subplot(2,1,1); 
plot(t,u,'b','LineWidth',2); 
grid on; 
title('Spriegums'); 
xlabel('Laiks (s)'); 
ylabel('U (V)'); 
subplot(2,1,2) 
plot(t,du,'r','LineWidth',2); 
grid on; 
title('Sprieguma izmainas atrums'); 
xlabel('Laiks (s)'); 
ylabel('du/dt (V/s)');