Which of the following expressions is in standard form for complex numbers?

Question

 

a.  

b.

c.

d.

 

Answer 1

standard form is a + bi

where a and b are real numbers

only a) is in standard form

a) 7-4i is in standard form with a= 7 and b = -4

b) i^2 + 5i is close. Just change i^2 to -1, then -1 +5i is in standard form with a=-1 and b=5

c) sqr(-5) = isqr5 where a=0 and b=sqr5

d) 4i^2 = -4 where a=-4 and b=0

d0

Answer 2

Only #1 is in standard form.