Find the x- and y- intercepts of the graphs of 5x-8y=40. State each answer as an integer or an improper fraction in simplest form.

z₁ × z₂ = 12·cis(2·π)

Step-by-step explanation:

z₁ = 4·cis(π/2), z₂ = 3·cis(3·π/2)

We have;

z₁ = 4·cis(π/2) = 4·(cos(π/2) + i·sin(π/2))

z₂ = 3·cis(3·π/2) = 3·(cos(3·π/2) + i·sin(3·π/2))

According to De Moivre's Theorem,

z₁ × z₂ = 4×3×(cos(π/2 + 3·π/2) + i·sin(π/2 + 3·π/2)) = 12·(cos(2·π) + i·sin(2·π))

∴ z₁ × z₂ = 12·cis(2·π)