Supplementary angles are angles that add up to 180 degrees
Answer = 180 - 142 = 38 degrees
(2+2i)(5+3i)
10+6i+10i+6i^2
10+16i+6(-1)
4+16i
When you have an “i^2”, you also have a negative one. The simplified answer is 4+16i
<span>arccos (cos pi/2)=?
</span>cos pi/2=0, arccos (0)=?, we know that cos pi/2=0, so cos^-1 (o)= Pi/2, but cos^-1 (o)=arccos (0), so arccos (cos pi/2)=Pi/2
