the expression (2+3i)^2 is equal to?
回答 (10)
2009-01-02 10:16 am
✔ 最佳答案
(2+3i)^2=(2+3i)(2+3i) use the FOIL
=4+12i+9i^2
=4+12i+9(-1) i^2 is equivalent to =4+12i-9
=12i-5 answer @(^_^)@
2009-01-02 10:11 am
(2 + 3i)^2 is the same as (2 + 3i) (2 + 3i).
This should give you 4 + 12i + 9i^2
Remember (a + b)(a + b) gives a^2 + 2ab + b^2
This should give you 4 + 12i + 9i^2
Remember (a + b)(a + b) gives a^2 + 2ab + b^2
2009-01-02 10:04 am
12i-5
2009-01-02 10:00 am
-5+12i
2009-01-02 9:59 am
4 + (3i)² + 12 i
4 - 9 + 12i
- 5 + 12 i
4 - 9 + 12i
- 5 + 12 i
2009-01-05 9:11 am
(2 + 3i)^2 = (2)^2 + (3i)^2 + 2(2)(3i)
= 4 - 9 + 12i
= -5 + 12i Answer.
= 4 - 9 + 12i
= -5 + 12i Answer.
參考: Any complex number book.
2009-01-02 10:55 am
-5+12i
2009-01-02 10:16 am
(2 + 3i)^2
= (2 + 3i)(2 + 3i)
= 2*2 + 3i*2 + 2*3i + 3i*3i
= 4 + 6i + 6i + 9i^2
= 4 + 12i + 9(-1)
= 12i + 4 - 9
= 12i - 5
= (2 + 3i)(2 + 3i)
= 2*2 + 3i*2 + 2*3i + 3i*3i
= 4 + 6i + 6i + 9i^2
= 4 + 12i + 9(-1)
= 12i + 4 - 9
= 12i - 5
2009-01-02 10:01 am
I got it and thought really hard about it and I know the answer.
The answer is
4+12i+(3i)^2
I'll prove it.
Let's say i=3
4+12(3)=40
(3*3)^2=81
81+40=121
Now watch this
(2+3*3)^2=121
-5+12(3) does not equal 121 so those can't be the answer
The answer is
4+12i+(3i)^2
I'll prove it.
Let's say i=3
4+12(3)=40
(3*3)^2=81
81+40=121
Now watch this
(2+3*3)^2=121
-5+12(3) does not equal 121 so those can't be the answer
2009-01-02 10:15 am
(2 + 3i)² = 2² + 6i + 9i² = 4 + 6i - 9 = -5 + 6i
收錄日期: 2021-05-01 11:44:32
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