Identify integral: Identify the integral to be solved.We have the integral:∫07π/4tan(7x)dx
Use substitution: Use a substitution to simplify the integral.Let u=7x, which implies that x=7u. Then, we need to find dx in terms of du.dx=7du
Change limits: Change the limits of integration according to the substitution.When x=0, u=70=0.When x=47π, u=7(7π/4)=4π.So the new limits of integration are from u=0 to u=4π.
Rewrite in terms of u: Rewrite the integral in terms of u.∫04πtan(u)⋅7du
Factor out constant: Factor out the constant from the integral. 7×∫04πtan(u)du
Integrate tan(u): Integrate tan(u) with respect to u. The integral of tan(u) is −ln∣cos(u)∣. So we have: 7×[−ln∣cos(u)∣] evaluated from 0 to 4π
Evaluate at limits: Evaluate the antiderivative at the upper and lower limits.7×[−ln∣cos(π/4)∣+ln∣cos(0)∣]= 7×[−ln(2/2)+ln(1)]= 7×[0−(−ln(2/2))]= 7×ln(2/2)
Simplify expression: Simplify the expression.7⋅ln(2/2)=7⋅ln(1/2)=7⋅ln(2(−1/2))=7⋅(−1/2)⋅ln(2)=−27⋅ln(2)
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