MATLAB: How to plot a line graph with algebraic function

Question

i have this equation y = -3.546x^4 + 40.652x^3 – 172.24x^2 + 320.58x – 221.62 i dont know how to plot it all i can get is like a wave graph. i cant get it to be curved graph. please help me

Answer 1

r = -3.546*Led.^4 + 40.652*Led.^3 - 172.24*Led.^2 + 320.58*Led - 221.62;
plot(Led, r)