Answer:
14(cos(125°) +i·sin(125°))
Step-by-step explanation:
The product of two complex numbers is the product of their magnitudes at an angle equal to the sum of their angles.
Application
For A = a·cis(α) and B = b·cis(β), the product AB is ...
AB = (a·cis(α))·(b·cis(β)) = ab·cis(α+β)
where "cis(x)" stands for the sum (cos(x) +i·sin(x)).
The product of interest is ...
Z1·Z2 = (7cis(15°))·(2cis(110°)) = (7·2)cis(15°+110°)
Z1·Z2 = 14cis(125°) = 14(cos(125°) +i·sin(125°))
