Neutral Current Calculation

I need neutral current calculation in wye and delta system and formula. What is the affect of power factor on neutral current. I know the below formula to calculate the neutral current.

In = √((Ia²+Ib²+Ic²)-(Ia*Ib)-(Ib*Ic)-(Ia*Ic))

But my friend says that the above formula is only resistive load not for load with power factor. He says if we have below condition we can not apply the above formula

Ia = 50 ampere with 0.76 p.f

Ib = 60 ampere with 0.85 p.f

Ic = 65 Ampere with 0.7 p.f

Hope to give some explaination.

thanks in advance.