Question

How do you solve `cosx=0.84` and find all solutions in the interval `[0,2pi)`?

Answer 1

`32^@86; 327^@14`

Explanation:

cos x = 0.84
Calculator and unit circle give:
`x = +- 32^@86`
Since the arc `(-32^@86)` is co-terminal to the arc `(327^@14)`,
so, the answers for (0, 360) are;
`x = 32^@86` , and `x = 327^@14`