calculating each of the products
noting that i² = (√- 1 )² = - 1
(1 + 2i)(8i) ( distribute by 8i )
= 8i + 16i² = - 16 + 8i ← complex number
(1 + 2i)(2 - 5i) ( expand using FOIL )
= 2 - 5i + 4i - 10i²
= 2 - i + 10 = 12 - i ← complex number
(1 + 2i)(1 - 2i) ( expand using FOIL )
= 1 - 2i + 2i - 4i²
= 1 + 4 = 5 ← real number
(1 + 2i)(4i) ( distribute by 4i )
= 4i +8i² = - 8 + 4i ← complex number
(1 + 2i)(1 - 2i) is the only product which results in a real number
Answer:
(-1,0)
Step-by-step explanation:
It is decreasing when the "slope" of the function is negative. That only happens on the blue curve from x = -1 to x = 0. In interval notation, that's (-1,0)
Multiply all sides than you will get you answer
I don't know about the first one but for the second one:
I can’t see a picture of the grid
