How do you divide ( -i+4) / (2i +7 )i+42i+7 in trigonometric form?

1 Answer
Jun 28, 2018

color(violet)((4 -i) / (7 + 2i) ~~ 0.4905 + i 0.28314i7+2i0.4905+i0.2831

Explanation:

To divide (4 - i) / (7 + 2i)4i7+2i using trigonometric form.

z_1 = (4 - i), z_2 = (7 + 2i)z1=(4i),z2=(7+2i)

#r_1 = sqrt(4^2 + 1^2) = sqrt 17

r_2 = sqrt(7^2 + -2^2) = sqrt53r2=72+22=53

theta_1 = arctan (-1/4) = 345.96^@, " IV quadrant"θ1=arctan(14)=345.96, IV quadrant

Theta_2 = arctan(2/7) = 15.95^@, " I quadrant"

z_1 / z_2 = (r_1 / r_2) * (cos (theta_1 - theta_2) + i sin (theta_1 - theta_2))

z_1 / z_2 = sqrt(17/53) * (cos (345.96 - 15.95 ) + i sin (345.96 - 15.95 ))

z_1 / z_2 = 0.5664 * (cos (-330.01) + i sin (-330.01))

color(violet)((4 -i) / (7 + 2i) ~~ 0.4905 + i 0.2831