Write the complex number in the form a + bi. 5/2 (cos 150° + i sin 150°)

1) cos (150°) = - cos (180°-150°) = - cos (30°) and - cos30° = - √ (3) / 2

sin (150°) = sin (180°-150°) = sin30. and sin30° = 1/2

Then : 5/2 (cos 150° + i sin 150°) becomes : 5/2{ (-√ (3) / 2 + I (1/2) ]

OR 5/4 ( - √3 + i)