Given Expression: We are given the expression secx−tanx1−secx+tanx1. To simplify this expression, we will find a common denominator and combine the fractions.
Find Common Denominator: The common denominator for the two fractions secx−tanx1 and secx+tanx1 is (secx−tanx)(secx+tanx). We will multiply the numerator and denominator of each fraction by the conjugate of its denominator to get the common denominator.
Multiply by Conjugate: For the first fraction, we multiply the numerator and denominator by secx+tanx:secx−tanx1⋅secx+tanxsecx+tanx=(secx−tanx)(secx+tanx)secx+tanx.
Combine Fractions: For the second fraction, we multiply the numerator and denominator by secx−tanx:secx+tanx1⋅secx−tanxsecx−tanx=(secx+tanx)(secx−tanx)secx−tanx.
Subtract Numerators: Now we combine the two fractions with the common denominator:(secx−tanx)(secx+tanx)secx+tanx−(secx+tanx)(secx−tanx)secx−tanx.
Simplify Numerator: We subtract the numerators and keep the common denominator:(secx−tanx)(secx+tanx)(secx+tanx)−(secx−tanx).
Denominator Simplification: Simplify the numerator by combining like terms:secx+tanx−secx+tanx=2tanx.
Apply Pythagorean Identity: The denominator is the product of a binomial and its conjugate, which is a difference of squares:(secx−tanx)(secx+tanx)=sec2x−tan2x.
Final Simplified Expression: We know that sec2x−tan2x=1 from the Pythagorean identity for secant and tangent:sec2x=1+tan2x, so sec2x−tan2x=1.
Final Simplified Expression: We know that sec2x−tan2x=1 from the Pythagorean identity for secant and tangent:sec2x=1+tan2x, so sec2x−tan2x=1.Now we can write the simplified expression:12tanx=2tanx.
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