Apologies, if the question has some error since my knowledge of statistics is limited. I am trying to predict DV using 9 IV. Using curve fit option in SPSS, I am finding that 6 of my IV have higher $R^2$ when a logarithmic or cubic curve is used over linear one.
I am confused, in such scenario. should I be transforming my variables and then run linear regression or should I use non-linear regression option??