Answer:
Explanation:
To solve this equation, we can start by using the identity cos(A-B) = cosAcosB + sinAsinB. Substituting A=sin x and B=1, we have:
2cos(sin x - 1) = cos(sin x)cos(1) + sin(sin x)sin(1)
We can then substitute this expression on the left-hand side of the original equation and simplify:
4sinxcosx^2 - 1 = cos(sin x)cos(1) + sin(sin x)sin(1)
Rearranging terms, we have:
4sinxcosx^2 - cos(sin x)cos(1) - sin(sin x)sin(1) = 1
We can now use the identity sin^2x+cos^2x=1 to simplify the left-hand side further:
4sinxcosx^2 - (sin^2x + cos^2x)cos(1) = 1
Simplifying further:
4sinxcosx^2 - (cosx)cos(1) = 1
Now we can divide both sides by cos(1):
4sinxcosx^2/cos(1) - cosx = 1/cos(1)
Rearranging terms:
cosx(4sinxcosx^2/cos(1) - 1) = 1/cos(1)
Finally, we can use the identity cos2x = 2cos^2x - 1 to simplify the left-hand side further:
(2cos^2x - 1)(4sinxcosx^2/cos(1) - 1) = 1/cos(1)
We can then divide both sides by (4sinxcosx^2/cos(1) - 1):
2cos^2x - 1 = 1/cos(1) (4sinxcosx^2/cos(1) - 1)
And finally, we can solve for cosx:
cosx = 1/2 + 1/2cos(1) (4sinxcosx^2/cos(1) - 1)
This is the solution to the equation.