9514 1404 393
Answer:
Step-by-step explanation:
The conjugate is found by changing the sign of the square root term.‡ (For this purpose, i = √-1.)
a) the sign of 3i is changed: 2 + 3i
b) the sign of sqrt(-5) is changed: 8 -sqrt(-5) = 8 -i√5
c) the sign of 2i is changed: 7 +2i
d) the sign of sqrt(7) is changed: 4 +√7
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‡ Actually, the conjugate of a binomial is formed by changing the sign <em>between</em> terms. The purpose is to allow the product of the binomial and its conjugate to be the difference of squares.
Conventionally, the conjugate of a complex number is the value with the sign of the imaginary part reversed. That is why (-2i+7)* = 7+2i.
9514 1404 393
Answer:
D. 86°
Step-by-step explanation:
Points D and F divide the circle into two arcs. The long arc is labeled 274°, and the short arc is the one you're asked to find. You know the total of these two arcs is the full circle, 360°.
274° + DF = 360°
DF = 360° -274°
DF = 86°
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There are other relationships you can use to find arc DF. One of the simpler ones is ...
DF and the external angle at E are supplementary:
DF = 180° -94° = 86°
Answer:
125°
Step-by-step explanation:
x + 24 is equal to 1.
6 is equal to 4x + 1
1 and 4x + 1 = 180°
x + 24 + 4x + 1 = 180
4x + x + 24 + 1 = 180
5x + 25 = 180
5x = 180 - 25
5x = 155
5x/5 = 155/5
x = 31
(angle) 6 = 4x + 1
(angle) 6 = 4(31) + 1
(angle) 6 = 124 + 1
(angle) 6 = 125°
