Solve on the interval please help!

Mathematics

1 answer:

Licemer1 [7]2 years ago

7 0

Answer:

Ф = 2pi/3 , 4pi/3

Step-by-step explanation:

1 + cos Ф = 1/2

Subtract 1 from each side

1 + cos Ф -1 = 1/2-1

cos Ф = -1/2

Take the inverse cos of each side

cos^-1 ( cos Ф )= cos^-1(-1/2)

There are two solutions for the inverse cos of (-1/2), 2pi/3 and 4pi/3

Ф = 2pi/3 +2 npi

Ф = 4pi/3 + 2n pi where n is an integer

We are limited to the interval between 0 and 2pi

Ф = 2pi/3 , 4pi/3

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