compond angle formula and adding ac currents?

**1. The problem statement, all variables and given/known data**

two alternating currents I1 and I2 flow into a circuit node,the output current I is given by adding I1 and I 2.

find I and t, when I1 and I2 are as follows

**2. Relevant equations**

I1=5sin(50t +Pi/3)

I2=6cos50t

**3. The attempt at a solution**

i1=sin(a+b)=sina.sinb+cosa.cosb

i1=sin50t x cos 60 + sin60 x cos60t x by 1/2 gives

i1=2.5sin50t + 4.33 x cos50t

Hi guys help required on above question please not sure where this progresses

thanks