Math Problem Statement

Consider the expression e^x - ln(cos^2(x)) + ln(1 + tan^2(x)) and then simplify it into a single term.

Solution

To simplify the expression given:

exln(cos2(x))+ln(1+tan2(x))e^x - \ln(\cos^2(x)) + \ln(1 + \tan^2(x))

we can break it down step-by-step and use properties of logarithms and trigonometric identities.

Step 1: Simplify ln(cos2(x))\ln(\cos^2(x))

Using the logarithmic property ln(ab)=bln(a)\ln(a^b) = b \cdot \ln(a), we get: ln(cos2(x))=2ln(cos(x))\ln(\cos^2(x)) = 2 \ln(\cos(x))

So, the expression becomes: ex2ln(cos(x))+ln(1+tan2(x))e^x - 2 \ln(\cos(x)) + \ln(1 + \tan^2(x))

Step 2: Simplify ln(1+tan2(x))\ln(1 + \tan^2(x))

Using the trigonometric identity 1+tan2(x)=sec2(x)1 + \tan^2(x) = \sec^2(x), we replace 1+tan2(x)1 + \tan^2(x) with sec2(x)\sec^2(x): ln(1+tan2(x))=ln(sec2(x))=2ln(sec(x))\ln(1 + \tan^2(x)) = \ln(\sec^2(x)) = 2 \ln(\sec(x))

Step 3: Substitute and Combine Terms

Now the expression is: ex2ln(cos(x))+2ln(sec(x))e^x - 2 \ln(\cos(x)) + 2 \ln(\sec(x))

Using sec(x)=1cos(x)\sec(x) = \frac{1}{\cos(x)}, we have: ln(sec(x))=ln(cos(x))\ln(\sec(x)) = -\ln(\cos(x)) Thus, 2ln(sec(x))=2ln(cos(x))2 \ln(\sec(x)) = -2 \ln(\cos(x)).

Substituting this back in, we get: ex2ln(cos(x))2ln(cos(x))=exe^x - 2 \ln(\cos(x)) - 2 \ln(\cos(x)) = e^x

Final Answer

The simplified expression is: exe^x

Would you like further clarification on any of the steps?


Additional Questions

  1. How would this simplification change if the expression had a different trigonometric function?
  2. What happens if we replace cos2(x)\cos^2(x) with sin2(x)\sin^2(x) in the expression?
  3. Can you simplify the expression if it included a different logarithmic function base, like log10\log_{10}?
  4. What other trigonometric identities can help simplify similar expressions?
  5. How would the approach differ if tan(x)\tan(x) was replaced by cot(x)\cot(x)?

Tip

Remember that recognizing trigonometric identities, such as 1+tan2(x)=sec2(x)1 + \tan^2(x) = \sec^2(x), can significantly simplify complex expressions.

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Math Problem Analysis

Mathematical Concepts

Exponential Functions
Logarithmic Functions
Trigonometry

Formulas

ln(a^b) = b * ln(a)
1 + tan^2(x) = sec^2(x)
sec(x) = 1 / cos(x)

Theorems

Logarithmic Properties
Trigonometric Identities

Suitable Grade Level

Undergraduate Level