Write Expressions: Write down the expressions to be added.We have two expressions: (1)/(1+cosx) and (1)/(1−cosx).
Find Common Denominator: Find a common denominator for the two expressions.The common denominator for (1+cosx) and (1−cosx) is (1+cosx)(1−cosx).
Rewrite with Common Denominator: Rewrite each fraction with the common denominator.The first fraction becomes ((1+cosx)(1−cosx)1−cosx) and the second fraction becomes ((1+cosx)(1−cosx)1+cosx).
Add Fractions: Add the two fractions.Now that they have a common denominator, we can add the numerators: (1−cosx)+(1+cosx).
Simplify Numerator: Simplify the numerator.When we add (1−cosx)+(1+cosx), the cosx terms cancel out, leaving us with 1+1, which equals 2.
Write Combined Fraction: Write the combined fraction.The combined fraction is now ((1+cosx)(1−cosx)2).
Simplify Denominator: Simplify the denominator.We recognize that (1+cosx)(1−cosx) is the difference of squares, which simplifies to 1−cos2x.
Recognize Pythagorean Identity: Recognize the Pythagorean identity.We know that cos2x+sin2x=1, so 1−cos2x=sin2x.
Substitute Identity: Substitute the identity into the denominator.The denominator becomes sin2x, so the fraction is now sin2x2.
Write Final Form: Write the final simplified form.The final simplified form of the sum is sin2x2.