Question

Solve sec x = 1.788, 0°<x<720° ?

Answer 1

`60^@, 300^@; 420^@; 660^@`

Explanation:

sec x = 1.788
`cos x = 1/(sec x) = 1/1.788 = 0.559`.
Calculator and unit circle give 2 solutions for x -->
`x = +- 60^@ + k360^@`
Note: `x = - 60^@` is co-terminal to `x = 300^@`
Answers for (0, 720):
`x = 60^@, x = 300^@; x = 420^@; x = 660^@`