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(i) int e^(x). "[log (sec x+tan x) + sec...

`(i) int e^(x). "[log (sec x+tan x) + sec x dx "`
`(ii) int (e^(-x)(cos x-sin x))/(cos^(2) x) dx`

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Let's solve the given integrals step by step. ### Part (i): We need to evaluate the integral: \[ I_1 = \int e^x \left( \log(\sec x + \tan x) + \sec x \right) dx \] **Step 1: Identify \(f(x)\) and \(f'(x)\)** Let: \[ f(x) = \log(\sec x + \tan x) \] Then, we need to find \(f'(x)\): \[ f'(x) = \frac{d}{dx} \log(\sec x + \tan x) = \frac{1}{\sec x + \tan x} \cdot \left(\sec x \tan x + \sec^2 x\right) \] This simplifies to: \[ f'(x) = \frac{\sec x (\tan x + \sec x)}{\sec x + \tan x} = \sec x \] **Step 2: Apply the standard result** The standard result states: \[ \int e^x [f(x) + f'(x)] dx = e^x f(x) + C \] In our case: \[ \int e^x \left( \log(\sec x + \tan x) + \sec x \right) dx = e^x \log(\sec x + \tan x) + C \] Thus, the solution to the first part is: \[ I_1 = e^x \log(\sec x + \tan x) + C \] ### Part (ii): We need to evaluate the integral: \[ I_2 = \int \frac{e^{-x} (\cos x - \sin x)}{\cos^2 x} dx \] **Step 1: Substitute** Let: \[ t = -x \implies dx = -dt \] Then, substituting into the integral: \[ I_2 = \int \frac{e^t (\cos(-t) - \sin(-t))}{\cos^2(-t)} (-dt) = -\int \frac{e^t (\cos t + \sin t)}{\cos^2 t} dt \] This can be rewritten as: \[ I_2 = \int \frac{e^t (\cos t + \sin t)}{\cos^2 t} dt \] **Step 2: Simplify the integral** We can split the integral: \[ I_2 = \int e^t \sec^2 t dt + \int e^t \tan t \sec t dt \] **Step 3: Apply the standard result** Let: \[ f(t) = \sec t \quad \text{and} \quad f'(t) = \sec t \tan t \] Using the standard result: \[ \int e^t [f(t) + f'(t)] dt = e^t f(t) + C \] Thus: \[ I_2 = e^t \sec t + C \] **Step 4: Substitute back for \(t\)** Substituting back \(t = -x\): \[ I_2 = e^{-x} \sec(-x) + C = e^{-x} \sec x + C \] ### Final Answers: 1. \(I_1 = e^x \log(\sec x + \tan x) + C\) 2. \(I_2 = e^{-x} \sec x + C\)
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