If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( x )
5*x^3 = 0
5*x^3 = 0
5*x^3 = 0
5*x^3 = 0 // : 5
x^3 = 0
x = 0
x in (-oo:0) U (0:+oo)
(30*x^4)/(5*x^3) = 0
6*x = 0 // : 6
x = 0
x in { 0}
x belongs to the empty set
| 4x/7+3=15 | | 2((2x+1)+x)=92 | | 2x-1=10x+4 | | a^2-12ad+36d^2= | | 2a+3-4+6= | | 2x^2+x-92=0 | | 5(c-4)+2(x+1)=3(2-4x) | | x^3(2x)(x+2)=90 | | -2y-x-7=0 | | x=ln(1.414141) | | 3x/5-1=17 | | x=ln(2^1/2) | | 1.5(12x-8)=-6x-4 | | 2(3x-3)=2(5x-4)+2(3-x) | | 5mn-4mn+2mn-3= | | 120=20t+5t | | 9*(P+10)=8(P-7) | | 11.2/1.75 | | x^2=0.512 | | 5*(r+5)=8*(r-9) | | -5(1+4x)=-17 | | (P=10)/(P-7)=8/9 | | 2-3p=-7 | | -0.5=d/4 | | 2B=mq+mk | | 3x-4(2-x)+10=7+5(2x-1) | | 4x+48=4x-12x | | 15x^4-20x^3=0 | | 3x^5-5x^4=0 | | .5(4x+16)+10x=12x+8 | | p-3/2q=1/2 | | 4x^2-5y^2-16x-30y-69=0 |