Kelly is trying to work out the two values of w for which 3w-w^3=2. Her values are 1 and -1. Are her values correct?
Sub in her values to see if the LHS and the RHS of the equation equate:
w=1: 3(1)-(1)^3=2 >>> 3-1=2 >>> 2=2 ✅
Therefore 1 is a correct value.
w=-1: 3(-1)-(-1)^3=2 >>> -3+1=2 >>> -2=2 ❎
Therefore -1 is not a correct value.
