If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( r )
r^4 = 0
r^4 = 0
r^4 = 0
1*r^4 = 0 // : 1
r^4 = 0
r = 0
r in (-oo:0) U (0:+oo)
36/(r^4) = 0
36*r^-4 = 0 // : 36
r^-4 = 0
r naleu017Cy do O
r belongs to the empty set
| 20x-12=64 | | 1=0.25k^2 | | 2r^2-5=27 | | 146.25=(3P)(0.11)+(P)(0.06) | | 9x^2+36x-288=0 | | 450=(12.5X/100)+X | | 450=(12.5X)+X | | 5x^2-6xy+5y^2-32=0 | | 8(3x-3)=-9(9+10) | | 3y+6/4+4y-9/5=9 | | -3p+8=5-(p+1) | | -3p+8=5(p+1) | | 11x-9y=4 | | 14=8-2x | | 2(4x-1)+x=8-x | | (14x+7)/7 | | (7u-11)^1/2=(9u-15)1/2 | | 5v^2=14v+3 | | 7/16*8/12 | | 7/16*1/7 | | 9/14-1/2 | | (Y+4)(y+1)=18 | | 8x^2+21=-58x | | -7W+5/3=-4/5w-4/3 | | x+-2x=10 | | 3x-25=1272 | | 23x+11y=-13 | | 1/6(5x-2)=8 | | 3(4x-3)-60x=39 | | Y(56)=14 | | 23/9+11/3+16/7 | | y=(9-8k)x |