Answer: optiob B.
Step-by-step explanation:
Remember that:
[tex]cos^2x+sin^2x=1[/tex]
Then, having the expression [tex](1-sinx)(1+sinx)[/tex], apply distributive property. Then:
[tex]=1+sinx-sinx-sin^2x[/tex]
Now you need to add the like terms:
[tex]=1-sin^2x[/tex]
If you solve for [tex]cos^2x[/tex] from [tex]cos^2x+sin^2x=1[/tex], you get: [tex]cos^2x=1-sin^2x[/tex]. Therefore the answer is:
[tex]=cos^2x[/tex]
