Simplify the Integral: Let's start by simplifying the integral. We know that sec(7x) is the reciprocal of cos(7x), so we can rewrite the integral as:∫(8e8sin(7x)⋅cos(7x))dxThis looks like a good candidate for a substitution because the derivative of sin(7x) is related to cos(7x).
Substitution with u: Let u=8sin(7x). Then, we need to find du in terms of dx. We know that the derivative of sin(7x) with respect to x is 7cos(7x), so:dxdu=8×7cos(7x)du=56cos(7x)dxNow we need to express cos(7x)dx in terms of du.
Express cos(7x)dx in terms of du: We have du=56cos(7x)dx, so we can solve for cos(7x)dx:cos(7x)dx=56duNow we can substitute u and 56du into the integral:∫(8eu⋅(56du))This simplifies to:71∫eudu
Substitute u back in: The integral of eu with respect to u is simply eu. So we have:(71)eu+CNow we need to substitute back in for u to get the integral in terms of x.
Final Answer: We originally let u=8sin(7x), so we substitute back in to get:71e8sin(7x)+C This is our final answer.
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