Why do i need to use .^ notation ?

Question

Yash Shil Balgobin 2021-4-3

评论： Yash Shil Balgobin 2021-4-3

Why do i need to use the .^ notation ? Is there any other way around it ?

% This is my function.
function y = PBTask4P1_f(x)
y = 4.2*x.^4-5*x.^3-7*x;
plot(x,y);
xlabel('INPUT X')
ylabel('OUTPUT Y')
end

Answer 1

KALYAN ACHARJYA 2021-4-3

编辑：KALYAN ACHARJYA 2021-4-3

It's based on equation. .^ represent the element wise to the power of any array/vector.

See the example

a =
     1     2     3     4     5     6
>> a.^2
ans =
     1     4     9    16    25    36

Whereas a^2=a*a (Matrix Multiplication)

But the above equation is not an array, is it ? If i remove the dots for y = 4.2*x^4-5*x^3-7*x;, the function fails.

@KALYAN ACHARJYA Thank you so much for the edit. It all makes sense now.