Answer:
A and C
Step-by-step explanation:
solving the equations
A
x² - 4 = 0 ( add 4 to both sides )
x² = 4 ( take square root of both sides )
x = ± = ± 2 ← required solution
B
x² = - 4 ← has no real solutions
C
4x² = 16 ( divide both sides by 4 )
x² = 4 ( take square root of both sides )
x = ± = ± 2 ← required solution
D
2(x - 2)² = 0 , then
x- 2 = 0 ( add 2 to both sides )
x = 2 ← not the required solution
9514 1404 393
Answer:
b = 71 m
A = 83°
C = 29°
Step-by-step explanation:
Many calculators can solve triangles. Apps are available for phone and tablet, or on the internet, like the one used here. In general, it takes less time to use one of these than to type your question into Brainly.
Given two sides and the angle between them, the Law of Cosines is the appropriate relation to use for finding the third side.
b = √(a² +c² -2ac·cos(B))
b = √(76² +37² -2·76·37·cos(67.75°)) ≈ √5015.48
b ≈ 70.82005 ≈ 71 . . . meters
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One a side and its opposite angle are known, the remaining angles are found using the Law of Sines.
sin(A)/a = sin(B)/b
A = arcsin(a·sin(B)/b) = arcsin(76·sin(67.75°)/70.82005) ≈ 83.33°
A ≈ 83°
C = arcsin(37·sin(67.75°)/70.82005) ≈ 28.92°
C ≈ 29°
Or, you can find the remaining angle from 180° -68° -83° = 29°.
