Given the function f (x) = cos2x - (cosx-1) cosx. (1) find the minimum value of function f (x) How are you going to deform?

Given the function f (x) = cos2x - (cosx-1) cosx. (1) find the minimum value of function f (x) How are you going to deform?

The original formula = 2cos & # 178; x-1-cos & # 178; X + cosx = cos & # 178; X + cosx-1

How to use matlab to draw the spectrum of an image

x = -2.9:0.1:2.9;
y = randn(10000,1);
hist(y,x)
This is the histogram drawn. I don't know if it's the spectrum you said?

Seeking directional derivative with MATLAB
Using MATLAB to find the directional derivative of the function u = XYZ in the direction AB from point a (5,1,2) to point B (9,4,14)

>> A=[5 1 2];>> B=[9 4 14];>> L=sqrt(sum((B-A).^2))L =13>> cosx=(B(1)-A(1))/L;>> cosy=(B(2)-A(2))/L;>> cosz=(B(3)-A(3))/L;>> syms x y z>> u=x*y*z;>> dudl=diff(u,x)*cosx+diff(u,y)*cosy+diff(u,z)*coszdu...

Why is the derivative of Y squared equal to 2Y times the derivative of Y

OK. Y squared derivative = 2Y * y derivative
The reason is that y here is a formula containing unknown variables, not a simple independent variable. For example, y ^ 2 = 2x, if you take the derivative of Y, it is equal to the derivative of 2Y * y