6. Compute the following and express answers in rectangular form: a. 10∠20 ∘
6+j4
​
+(14+j2) b. (1+j6)+[2+ 6−(10∠20 ∘
)(2∠−10 ∘
)
(12∠0 ∘
)(14+j2)
​
] 7. For Figure 16-18, determine i T
​
where i 1
​
=10sinωt,i 2
​
=20sin(ωt−90 ∘
), and i 3
​
=5sin(ωt+90 ∘
).