Question

Can someone help me on this?

Answer 1

Explanation:

We know that cosx = sin(
`\pi` - x)

We can apply it here:

sin(55°) = cosx

cos(
`\pi` - 55°) = cosx

Now we apply the arccos to both sides:

x =
`\pi` - 55° + 2k
`\pi` or x = -
`\pi` - 55° + 2k
`\pi`