Question

How do you solve `8cosx+3=4`?

Answer 1

`82^@82 + k(360^@)`
`277^@18 + k(360^@)`

Explanation:

8cos x + 3 = 4
8cos x = 1 --> `cos x = 1/8`
Use calculator and unit circle -->
`cos x = 1/8` --> `x = +- 82^@82`
Note: the arc (-82.82) is co-terminal to arc (360 - 82.82) = 277^@18
Answers for (0, 360):
`82^@82, 277^@18`
General answers:
`82^@82 + 2k(180^@)`
`277^@18 + 2k(180^@)`

Check by calculator.
`cos (277.18) = 0.1249 = 1/8` .OK