A) -square root of 2- square root of 2i
B) -2square root if (2)+2square root of 2i
C) -2square root of (2)- 2square root of 2i
D) -square root(2)+ square root of (2i)
If you hold down ALT and type 0176 on the number pad on the right of the keyboard,
you get the ° symbol.
Is the angle + or – 135° ?
It helps to put ( ) around the number to make it clear.
as in sin(135°) or cos(-135°).
If it’s +, then
cos 135° = – sqrt(2)/2
sin 135° = sqrt(2)/2
so plugging those into the expression,
we get answer (B)
which should be written as
-2 sqrt(2) + ( 2 sqrt(2) ) i
to avoid confusion as what is under the square root sign.
If the angle in question is -135°, then the sin function is also negative,
and the answer is (C)