MATLAB: What is wrong with the matlab codes? ( MATLAB) please help me!

Question

clear all;
clc
Vm=100;
Z=2;
angle_radians=pi*-0.5;
wt=0:0.01:(2*pi);
v=Vm*cos(wt);
Im=Vm/Z;
i=Im*cos((wt)-(angle_radians));
p=(v.*i);
pr=v*i*cos(angle_radians)*(1+cos(2*wt)); 
px=v*i*sin(angle_radians)*(1+sin(2*wt)); 
subplot(4,1,1);plot(wt,v,wt,i);title('v(t)=Vmcoswt,I(t)=Imcos(wt+-(-90)');
xlabel('time');
ylabel('voltage (volts) & Current (Amps)');
subplot(4,1,2);plot(wt,p);title('p(t)=v(t)i(t)');
xlabel('time (t)'); 
ylabel('power (Watts)');
subplot(4,1,3);plot(wt,pr);title('pr(t)');
xlabel('time (t)'); 
ylabel('pr(t)');
subplot(4,1,4);plot(t,i);title('px(t)');
xlabel('time (t)'); 
ylabel('px(t))');
grid;

I am trying to draw graphs about reactive power etc. What can be wrong with line 13 and matrix?

Answer 1

Please replace the all * with .* for element wise product

and in line no 31, you neet to replace t with wt