Find the Definite Integrals : `int_-(pi/4)^0 e^(tanx) sec^2 x dx `

Explanation

To solve the definite integral \(\int_{-\frac{\pi}{4}}^{0} e^{\tan x} \sec^2 x \, dx\), we will use the method of substitution. Here are the steps:

### Step 1: Choose a substitution
Let \( z = \tan x \).

### Step 2: Differentiate to find \( dz \)
Differentiating both sides gives:
\[
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