Identify Integral: Identify the integral that needs to be solved.We need to find the indefinite integral of the function 7x2+81 with respect to x.
Recognize Form: Recognize the form of the integral. The integral is of the form ∫ax2+bdx, which suggests a trigonometric substitution or a direct comparison to the standard integral form ∫x2+a2dx, which results in a1arctanax + C.
Perform Substitution: Perform a substitution to match the standard form.Let's compare 7x2+8 to the standard form x2+a2. We can rewrite the integral as ∫7(x2+(8/7))dx.
Factor Out Constant: Factor out the constant from the denominator.We can factor out the 7 from the denominator to match the standard form. The integral becomes (1/7)∫dx/(x2+(8/7)).
Complete Square:Complete the square in the denominator.To complete the square, we need to have a perfect square in the denominator. We already have that since (78) is a constant term. So, we can write the integral as (71)∫x2+(78)2dx.
Apply Standard Form: Apply the standard integral form.Now we can apply the standard integral form ∫x2+a2dx=a1arctan(ax)+C. Here, a=78, so the integral becomes 781arctan(78x)+C.
Simplify Expression: Simplify the expression.Simplify the expression to get the final answer. We have (781)arctan(78x)+C=(87)arctan(x87)+C.
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