Question

Write the complex number in the form a + bi.

Answer 1

If you draw the angle in a unit circle, you'll see that it is equal to -45 degrees, so there is an a-a-asqrt(2) triangle involved...(hope this sounds familiar).
It means you know the exact values of cos and sin of 315 (=-45). They are:

cos 315 = ½√2
sin 315 = -½√2

Put these numbers in and expand the brackets to see what answer you get.

Answer 2

is it the second one