Answer:
x ∈ {2π/3, π, 4π/3} ≈ {2.09440, 3.14159, 4.18879}
Step-by-step explanation:
The equation can be put into standard form by adding 1:
2cos²(x) +3cos(x) +1 = 0
(2cos(x) +1)(cos(x) +1) = 0
Values of cos(x) that make this true* are ...
cos(x) = -1/2 . . . . . . . . . true for x=2π/3, x=4π/3
cos(x) = -1 . . . . . . . . . . . true for x=π
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A graphing calculator can be helpful here, too.
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* from your knowledge of the short table of trig functions and their signs in different quadrants
-19u + 11 = -20u
Add 19u to both sides.
11 = -u
Divide both sides by -1.
-11 = u
Answer:
c
Step-by-step explanation:
simplify and find x intercepts
Answer:
w = 4 ft
diagonal= 13 ft
l= 13^2-4^2=169-16 = sq root 153
=12.4 ft (approx)
Answer: (D) 1.99x + 1.89y = 9.57
Step-by-step explanation: The reason is because equation option D states that for every notepad and pencil, x and y he bought, the total of his bill would equal $9.57.