### Related

##### realroots-solve

solve(144+x^2);

realroots(784+(30-x)^2);

Calculate

##### realroots

realroots(3*x^4-x^3+1...

Calculate

##### realroots-solve

p(x):=-100+20*x+25*x^...

solve([p(x)=0],[x]);

realroots(p(x));

Calculate

f:2*n^2 +7*n+6;

realroots(f);

Calculate

##### realroots-true

%e_to_numlog:true;

realroots(3=10*log10(...

Calculate

##### realroots

ursprungspreis: 199;

verkaufspreis:183.98;

g:verkaufspreis=urspr...

Calculate

##### realroots

y(x):=-0.08*x^2+x+40;

N:realroots(y(x));

Calculate

##### realroots

(realroots(7*x+1*x+-5...

Calculate

##### realroots-solve

realroots(-6*x+4*x+3=0);

solve(-6*x+4*x+3=0,x);

Calculate

r:2003.429;

a:3.87e-3;

d:1.319;

Calculate

### realroots

Run Example
(%i1)define(fp(x), 3*x^2 - 4*x);
2
(%o1)                         fp(x) := 3 x  - 4 x
(%i2) float(realroots(fp(x)=0));
(%o2)                  [x = 1.333333343267441, x = 0.0]
(%i3) fp(-1);
(%o3)                                  7
(%i4) fp(1);
(%o4)                                 - 1
(%i5) fp(5);
(%o5)                                 55
(%i6)
Run Example
define( f(x), x^3-20*x^2+5*x-20 );
3       2
(%o1)                    f(x) := x  - 20 x  + 5 x - 20
(%i2) define( fp(x),diff(f(x),x) );
2
(%o2)                      fp(x) := 3 x  - 40 x + 5
(%i3) define( fpp(x),diff(fp(x),x) );
(%o3)                         fpp(x) := 6 x - 40
(%i4) factor( fpp(x) );
(%o4)                            2 (3 x - 20)
(%i5) plot2d( f(x), [x,-4,3] );
plotc : float(realroots( fp(x)=0 ));
(%o6)            [x = 0.12619438767433, x = 13.20713898539543]
(%i7) f(c);
3       2
(%o7) [x  - 20 x  + 5 x - 20 = - 19.68551888265151,
3       2
x  - 20 x  + 5 x - 20 = - 1138.832999635867]
(%i8) integrate(f(x),x,-2,2);
560
(%o8)                                - ---
3
(%i9) define( F(x),C+integrate(f(x),x) );
4       3      2
x    20 x    5 x
(%o9)                F(x) := C + -- - ----- + ---- - 20 x
4      3      2
(%i10) realroots( F(0)=4 );
(%o10)                              [C = 4]
(%i11)
Run Example
p(x):=0.11*x**2-1.5*x+4.39;
2
(%o1)                   p(x) := 0.11 x  - 1.5 x + 4.39
(%i2) l:realroots(p(x)),numer;
(%o2)           [x = 4.253320723772049, x = 9.383042901754379]
(%i3) xs:x,l[1];
(%o3)                          4.253320723772049
(%i4) xs:floor(xs*100+0.5)/100.0;
(%o4)                                4.25
(%i5) p:p(x),x=xs;
(%o5)                         0.0018749999999992
(%i6) p:floor(p*100+0.5)/100.0;
(%o6)                                 0.0
(%i7)

### Related Help

Help for Realroots