Question

Solve for x on the domain 0 < x < 12: cos x= -0.814

Answer 1

Answer:

Replace 10.0 with 10.04

Step-by-step explanation:

$\cos(x) = - 0.814$

$\cos {}^{ - 1} ( - 0.814) = x$

$x = 2.52$

Next, use the identity

$\cos(x) = \cos(2\pi - x)$

$\cos(2.52) = \cos(2\pi - 2.52)$

$\cos(2.52) = \cos(6.28 - 2.52)$

$\cos(2.52) = \cos(3.76)$

So another solution is 3.76

After that, use the identity

$\cos(x + 2\pi) = \cos(x)$

So use that for 2.52 and 3.76

$\cos(2.52 + 2\pi) = \cos(8.80)$

8.80 is one solutiin

$\cos(3.76 + 2\pi) = \cos(10.04)$