Finding the angle of the total acceleration of a point?

A point on a rotating turntable 21.5 cm from the center accelerates from rest to a final speed of 0.740 m/s in 1.80 s. At t = 1.26 s,



I found:



Radial Acceleration: 1.25



Tangential Acceleration: .4096



Total Acceleration: 1.31





Now, I'm having problems finding the total acceleration angle?





I did:



.740/1.80=.411

tan^-1(.411/1.25) and I got 18.2, but that isn't right?



Thank you!