Solve the equation 2 cos ( x ) + 1 = 0 2 cos x + 1 = 0 , 0 ≤ x ≤ 2 π 0 ≤ x ≤ 2 π . Show all of your work
1 answer:
Answer:
2π/3, 4π/3
Step-by-step explanation:
I interpret your question as asking us to solve the equation
2cos(x) + 1 = 0
2cos(x) = -1
cos(x) = -½x
x = arccos(-½), 0 ≤ x ≤2π
Since the cosine is negative, x must be in the second or third quadrant.
Referring to the unit circle, we find that
x = 2π/3 (120°) or x = 4π/3 (240°)
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<u>Answer:</u>
The correct answer option is: 19, 13, 3, -11, -29.
<u>Step-by-step explanation:</u>
We are given the following explicit formula for an arithmetic sequence:
So to find the first five terms of this sequence, we will substitute the values of (num here in the given formula:
Therefore, the first five terms of the sequence defined by the explicit formula are 19, 13, 3, -11, -29.
Using the law of cosine for Triangle KJL, we can write:
Using the values of k,j and l, we can write:
Rounding to nearest integer, the measure of angle J will be 48 degrees.
So option B gives the correct answer
Using the values of k,j and l, we can write:
Rounding to nearest integer, the measure of angle J will be 48 degrees.
So option B gives the correct answer