1. The problem statement, all variables and given/known data A resistor with resistance R is connected to a battery that has emf 15.0[V] and internal resistance r = 0.38[Ω]. For what two values of R will the power dissipated in the resistor be 78.0 W? 2. Relevant equations P=I2R=(ε2/(R+r)2)R 3. The attempt at a solution ε2R=(R2+2Rr+r2)P R2+(2r-(ε2/P))R+r2=0 R=1/2[((ε2/P)-2r)±√(((ε2/P)-2r)2)-4r2 At this point I should be able to plug in what I know, and I get roughly R=1.06±0.77 However that is not right, I have tried again making sure I kept my sig figs in order and all that good stuff, I get a couple similar but different answers, still all wrong though. I have only one attempt left and it's worth 27% of the grade on this HW so any help would be appreciated greatly. This is an image of my attempts, the problem, and how the solutions manual did the quadratic.