DBM 10013 Pre Test 1B Sesi 1 2022/2023

• 10
• -10
• 10i
• -10i

Simplify
3i - (4 + 7i)

• -4 + 10i
• 21 - 12i
• 4 - 10i
• -4 - 4i

Find the sum.
(5-2i) + (-7+8i)

• -2+6i
• 12+6i
• -35-16i²
• -35 -16i

Multiply: 
(4 – 3i)(7 + 2i)

• A.  22 - 13i
• B.  28 - 19i
• C.  34 - 13i
• D.  -34 - 29i

Where is point C located?

• 2 + i

• -3

• 2i

• -1 - i

What is the conjugate of 5 - 2i?

• 5 + 2i

• -5 - 2i

• 5 - 2i

• -5 + 2i

Let  $z=-4\ +\ 3i$  , calculate the modulus and argument of z

•  $-4,\ 53.13^{\degree}$  
  

•  $3,\ 53.13^{\degree}$  

•  $5,\ 143.1^{\degree}$  

• Not Possible

Solve the above complex number in the form of a+bi

• 4/5 + (7/5)i

• -4/5 - (7/5)i

• -4/5 - 7/5i

• 4/5 - (7/5)i

• 50(cos145^o + i sin145^o)

• 15(cos145^o + i sin145^o)

• 81(cos100^o + i sin100^o)

• All Options are Correct

Write the complex number in polar form

• $\sqrt{50}\ \angle\ 45^{\degree}$

• $\sqrt{50}\ \left(\cos\ 45\degree\ +\ i\ \sin\ 45\degree\right)$
  

• $\sqrt{50}e^{0.7855i}$