Evaluate ` 2i^(2)+ 6i^(3)+3i^(16) -6i^(19) + 4i^(25) `

Evaluate (4+5i)(2-3i)

Evaluate (2+3i)(4-5i).

Find the value of i^(4) + i^(5) + i^(6) + i^(7) .

Evaluate : [i^(18)+(1/i)^(25)]^3

Simplify: i+ 2i^(2) + 3i^(3) + i^(4)

Evaluate: [i^(18) + ((1)/(i))^(25)]^(3)

Find the values of the following : (i) i^(7)+i^(17)+i^(12) (ii) i^(11)+i^(-11) (iii) i^(3)+(1)/(i^(3)) (iv) 1+i^(2)+i^(6)+i^(8)

Evaluate: [i^19+(1/i)^25]^2

Find the value of 1+i^(2)+i^(4)+i^(6)+...+i^(2n), where i=sqrt(-1) and n in N.