Cos 157.5º=-cos (180º-157.5º)=-cos 22.5=-cos(45/2)
cos Ф/2=⁺₋√((1+cosФ)/2).
In this case 157.5º is in the second quadrant, therefore we use the following equation:
cos Ф/2=-√((1+cosФ)/2). (we will have a negative number)
cos 157.5º=-cos (45/2)=-√((1+cos 45º)/2)
=-√((1+√2/2)/2)
=-√((2+√2)/4)
=-√(2+√2) / 2 (≈-0.92387...)
Answer: cos 157.5º= -√(2+√2) / 2
Answer:
84
Step-by-step explanation:
28*3
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Answer:
28
Step-by-step explanation:
49*364= 14924
14952 - 14924= 28
We will see that the solution in the given interval is: x = 0.349 radians.
<h3>How to solve equations with the variable in the argument of a cosine?</h3>
We want to solve:
cos(3*x) = 1/2
Here we must use the inverse cosine function, Acos(x). Remember that:
cos(Acos(x)) = Acos(cos(x)) = x.
If we apply that in both sides, we get:
Acos( cos(3x) ) = Acos(1/2)
3*x = Acos(1/2)
x = Acos(1/2)/3 = 0.349
So x is equal to 0.349 radians, which belongs to the given interval.
If you want to learn more about trigonometry, you can read:
brainly.com/question/8120556