### Related

##### combine-diff-display2d-false-first-plot2d-second-solve-third

display2d:false;

Q(t):=a + b*t + c*t*t;

I(t):=''(diff(Q(t), t));

Calculate

a = 1 /2;

b = 3/4;

c= a+b;

Calculate

##### combine

combine(1/(%i*w*L+R) ...

Calculate

eq1:1/(1+z^-1);

eq2:1/(1+eq1);

combine(eq2);

Calculate

Calculate

##### combine-cos-diff-sin

y:%e^x * ((-1/18*x^3 ...

diff(y, x, 2) + diff(...

combine(%);

Calculate

##### combine

combine(a^2+2*a^3);

Calculate

##### combine-expand-is-sqrt

is((-3*sqrt(7)-56)/7 ...

combine(-3*sqrt(7)/7-8);

expand((-3*sqrt(7)-56...

Calculate

Calculate

##### combine-cos-sin

a=cos(x)+%i*sin(x);

b=cos(y)+%i*sin(y);

c=cos(z)+%i*sin(z);

Calculate

### combine

Run Example
```(%i1)a=cos(x)+%i*sin(x);
(%o1)                       a = %i sin(x) + cos(x)
(%i2) ((a+b)-(c+d))/(a*b-c*d)-((b+c)-(a+d))/(b*c-a*d);
- d - c + b + a   - d + c + b - a
(%o2)                  --------------- - ---------------
a b - c d         b c - a d
(%i3) combine(%);
(%o3)             (%i4) ```
Run Example
```a: -3/10 + sqrt(141)/30;
sqrt(141)   3
(%o1)                           --------- - --
30       10
(%i2) c: combine(a);
sqrt(141) - 9
(%o2)                            -------------
30
(%i3) b: (-9+sqrt(141))/30;
sqrt(141) - 9
(%o3)                            -------------
30
(%i4) d: combine(b);
sqrt(141) - 9
(%o4)                            -------------
30
(%i5) is (a = b);
(%o5)                                false
(%i6) (-9 - sqrt(141))/30;
- sqrt(141) - 9
(%o6)                           ---------------
30
(%i7) ```
Run Example
```numerador:(a^x-a*b^(n-1)-a^(x-1)*b+b^n);
x    n      n - 1    x - 1
(%o1)                    a  + b  - a b      - a      b
(%o2)                                a - b
x        n
(b - a) (a  b - a b )
(%o3)                       - ---------------------
a b