### Related

##### del-diff

u:x+y^2*x;

diff(u);

diff(u,x)*del(x)+diff...

Calculate

P:32;

A:481;

H:1.6;

Calculate

##### del-numer-sqrt-sum

gp: (1+sqrt(3))/2;

gm: (1-sqrt(3))/2;

x: .155793;

Calculate

P:32;

A:481;

H:1.6;

Calculate

##### del-numer-sqrt-sum

gp: (1+sqrt(3))/2;

gm: (1-sqrt(3))/2;

x: .15581;

Calculate

##### del-numer-sqrt-sum

gp: (1+sqrt(3))/2;

gm: (1-sqrt(3))/2;

x: .15580;

Calculate

##### del-ode2

ode2(del(y) = y*del(x...

Calculate

##### del-integrate-sqrt

f: del(x)/(sqrt(1-x^2));

f1: integrate(f,x);

Calculate

##### del-sqrt

xK: [8.64066, 9.83436...

yK: [6.1, 10.4, 13.3];

xK1: [12.8953, 13.64,...

Calculate

##### del-numer-sqrt-sum

gp: (1+sqrt(3))/2;

gm: (1-sqrt(3))/2;

x: .1559;

Calculate

### del

Run Example
```(%i1)p[0]:x;
(%o1)                                  x
(%i2)  q[0]:1;
(%o2)                                  1
(%i3) p[n]:=a*p[n-1]^2+b*q[n-1]^2;
2          2
(%o3)                      p  := a p      + b q
n       n - 1      n - 1
(%i4) q[n]:=c*p[n-1]^2+d*q[n-1]^2;
2          2
(%o4)                      q  := c p      + d q
n       n - 1      n - 1
(%i5) del(m,n):=p[m]*q[n]-q[m]*p[n];
(%o5)                    ''del(m, n) := p  q  - q  p
m  n    m  n
(%i6) del(3,0);
(%o6)                              del(3, 0)
(%i7) q[3];
2     2         2     2 2            2     2         2     2 2
(%o7) d (d (c x  + d)  + c (a x  + b) )  + c (b (c x  + d)  + a (a x  + b) )
(%i8) ```
Run Example
```jacobian ([u+ (cos(v)-sin(v))*b*del(u)], [u, del(u), v]);
[                      d                ]
(%o1)  Col 1 = [ b (cos(v) - sin(v)) (-- (del(u))) + 1 ]
[                      du               ]
Col 2 = [ b (cos(v) - sin(v)) ] Col 3 = [ b (- sin(v) - cos(v)) del(u) ]
(%i2) ```
Run Example
```expr: x . dx . dy + z . dy . dz + y . dx . dz;
(%o1)               z . dy . dz + y . dx . dz + x . dx . dy
(%i2) expr2: x . [dx, dy] + z . [dy, dz] + y . [dx, dz];
(%o2)             z . [dy, dz] + y . [dx, dz] + x . [dx, dy]
(%i3) expr3: x * [dx, dy] + z * [dy, dz] + y * [dx, dz];
(%o3)              [dy z + dx y + dx x, dz z + dz y + dy x]
(%i4) expr4: [x, dx, dy] + [z, dy, dz] + [y, dx, dz];
(%o4)                  [z + y + x, dy + 2 dx, 2 dz + dy]
(%i5) expr5: [[x, dx, dy], [z, dy, dz], [y, dx, dz]];
(%o5)               [[x, dx, dy], [z, dy, dz], [y, dx, dz]]
(%i6) expr6: x . del(x) . del(y) + z . del(y) . del(z) + y . del(x) . del(z);
(%o6)   z . del(y) . del(z) + y . del(x) . del(z) + x . del(x) . del(y)
(%i7) part(expr, 1);
(%o7)                             z . dy . dz
(%i8) length(expr);
(%o8)                                  3
(%i9) op(expr);
(%o9)                                  +
(%i10) args(expr);
(%o10)              [z . dy . dz, y . dx . dz, x . dx . dy]
(%i11) map(op, args(expr));
(%o11)                             [., ., .]
(%i12) map(args, args(expr));
(%o12)              [[z, dy, dz], [y, dx, dz], [x, dx, dy]]
(%i13) map(args, args(expr6));
(%o13)  [[z, del(y), del(z)], [y, del(x), del(z)], [x, del(x), del(y)]]
(%i14) diffform(vars, expr) := block(    [n, k],    0);
(%o14)             diffform(vars, expr) := block([n, k], 0)
(%i15) diff(x + y);
(%o15)                          del(y) + del(x)
(%i16) ```

Help for Del