Answer: A, B, C, and E
Step-by-step explanation:
If both sides are real numbers, then the product will be a real number.
If in at least one of the sides we have a complex number, then the product will be real if:
The other number is zero.
The other number is the conjugate of the first.
This is when:
Suppose we have a number:
z = a + b*i
The conjugate will be:
w = a - b*i
And the product between them is:
(a + b*i)*(a - b*i) = a^2 + a*b*i - a*b*i + b^2 = a^2 + b^2
Then the options that will have a real answer are:
A. (4+5i)(4-5i) = 4^2 + 5^2 = 16 + 25 = 41
B. (4 + 91)*(41 - 9) = 3040
C. (3 + 2*i)*(3 -2*i) = 3^2 + 2^2 = 9 + 4 = 13
E. (312 + 7i)*(312 - 7i) = 312^2 + 7^2 = 97,393
Answer:
15.1°
Step-by-step explanation:
In ΔGHI, the measure of ∠I=90°, GH = 96 feet, and IG = 25 feet. Find the measure of ∠H to the nearest tenth of a degree.
We solve using sine rule
GH/sin I = lG/ sin H
96/sin 90 = 25/sin H
Cross Multiply
sin 90 × 25 = sin H × 96
sin H => sin 90 × 25/96
H => arc sin( sin 90 × 25/96)
H => 15.09479°
Approximately ∠H = 15.1°
Answer: oh that easy. The first one goes to the bottom right and the third one goes to the bottom left and the 4th one goes to the middle the 2nd one goes to the bottom right and the last one goes to the middle. :) have a nice day!
Step-by-step explanation:
Answer: 20% of 500= 100
So 500-100 = 400
4x100= 400
Step-by-step explanation:
