Find $( 7 + 4 i ) ^ { 2 }$ and express the answer in the standard form of a complex number.
A) 33 $-$ 56 i
B) $-$ 33 $-$ 56 i
C) 33 i + 56
D) 33 + 56 i

Name: Find $( 7 + 4 i ) ^ { 2 }$ and express the answer in the standard form of a complex number. A) 33 $-$ 56 i B) $-$ 33 $-$ 56 i C) 33 i + 56 D) 33 + 56 i
Brand: Quizplus
Rating: 4.8 (33 reviews)

Question

Quizplus · Accepted Answer

Use FOIL method to get $(7+4i)^2 = (7+4i)(7+4i) = 49+28i+28i+(4i)^2 = 49+56i+16i^2 = 49+56i-16 = \boxed{33+56i}$.

Find (7+4i)2( 7 + 4 i ) ^ { 2 }(7+4i)2

Find $( 7 + 4 i ) ^ { 2 }$