MATLAB: Help me to find two consecutive differentiation with respect to x

n/a

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If I remember my high-school algebra correctly, it's

q = 3*(1-cos(pi*x/10))= 3 - 3*cos(pi/10*x)
dq/dx = 3*sin(pi/10*x)*pi/10;
(d/dx)(dq/dx)= dq/dx^2 = 3*cos(pi/10*x)*pi^2/100;

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MATLAB: Rewrite A=[31] matrix to [33][31(var)]=A

Doing it by matrix division (the mldivide function) did not work because the rows are not consistent.

The only solution I can come up with is:

syms qd td ed q teta
E =[ ed*cos(q)*sin(teta) - cos(teta)*(qd*cos(q)*sin(teta) + td*cos(teta)*sin(q)) - td*sin(q)*sin(teta)^2 ; cos(teta)*(td*cos(teta)*sin(q) - qd*sin(q)*sin(teta)) + ed*sin(q)*sin(teta) + td*cos(q)*sin(teta)^2  ;  ed*cos(teta) + cos(q)*sin(teta)*(qd*cos(q)*sin(teta) + td*cos(teta)*sin(q)) - sin(q)*sin(teta)*(td*cos(teta)*sin(q) - qd*sin(q)*sin(teta))];
v = [qd;td;ed];
for k1 = 1:size(E,1)
    C{k1} = coeffs(E(k1), v);
end
Out = [C{1}; C{2}; C{3}]

The columns of ‘Out’ are with respect to the elements of ‘v’, in order. Change the order of ‘v’ to produce the result you want.

MATLAB: How to preallocate X

for aug = 1:168888%168888
    abc = 8;
    count = {};
    V = (abc);
    X = [X;[count V]];
end

Can be replaced by:

X=8*ones(1,168888);

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Related Solutions

MATLAB: Rewrite A=[3*1] matrix to [3*3]*[3*1(var)]=A

MATLAB: How to preallocate X

Related Question

MATLAB: Rewrite A=[31] matrix to [33][31(var)]=A