I2=100I12I_2=100I_1^2I2=100I12
I2=I12I0I_2=\dfrac{I_1^2}{I_0}I2=I0I12
I2=I1I0I_2=\dfrac{I_1}{I_0}I2=I0I1
I2=I12I02I_2=\dfrac{I_1^2}{I_0^2}I2=I02I12