# complex numbers

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#1
i have this question to do on my maple but i cant see where i've gone wrong

Convert the following number into the form p+iq where p and q are real.
Note: give your answer in the correct order, i.e. [p,q], in the boxes below.

4+4i
1+2i

this is my working

(4+4i)(1-2i)
(1+2i)(1-2i)

(4+8)(4-(-8))i
1²+2²

12+12i
5

2.4 + 2.4i

but it doesnt seem to like my answer 0
15 years ago
#2
(Original post by manps)
i have this question to do on my maple but i cant see where i've gone wrong

Convert the following number into the form p+iq where p and q are real.
Note: give your answer in the correct order, i.e. [p,q], in the boxes below.

4+4i
1+2i

(4+8)(4-(-8))i
1²+2²
check 4--8i

numerator: 4 + 8 + 4i - 8i

Aitch
0
15 years ago
#3
(Original post by manps)
i have this question to do on my maple but i cant see where i've gone wrong

Convert the following number into the form p+iq where p and q are real.
Note: give your answer in the correct order, i.e. [p,q], in the boxes below.

4+4i
1+2i

this is my working

(4+4i)(1-2i)
(1+2i)(1-2i)

(4+8)(4-(-8))i
1²+2²

12+12i
5

2.4 + 2.4i

but it doesnt seem to like my answer why? It;s wrong there. should be (4-8)i  0
#4
how do i do this please

Convert the following number into the form p+iq where p and q are real.

2/(1+2i) + 5/(3-4i)

0
15 years ago
#5
2(1-2i)/5 + 5(3+4i)/25
2-4i/5 + 3+4i/5= 1
0
#6
(Original post by BCHL85)
2(1-2i)/5 + 5(3+4i)/25
2-4i/5 + 3+4i/5= 1
hi
it says in the Q,
Note: give your answer in the correct order, i.e. [p,q], in the boxes below.
so wot wud the answer therefore be
0
15 years ago
#7
(Original post by manps)
hi
it says in the Q,
Note: give your answer in the correct order, i.e. [p,q], in the boxes below.
so wot wud the answer therefore be
1 and 0?

That's what the coords of the point on the Argand diagram would be.

Aitch
0
#8
one last Q

Find, in the form a + b i, where a and b are real, a square root of 3+4 i

not sure how to do this
0
15 years ago
#9
3+4i = (a+bi)² = a² - b² + 2abi
=> a²-b²=3
=> 2ab=4
Solve to find a & b.
0
#10
2+1i

cheers
0
15 years ago
#11
+/- 2+i 0
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