What is the integral of e^{7x}cos(2x) ?

The integral of e^{7x}cos(2x) is (2e^{7x}sin(2x))/(53)+(7e^{7x}cos(2x))/(53)+C

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integral of e^{7x}cos(2x)

\int e^{7 x} cos (2 x) d x

\frac{2 e ^{7 x} sin ( 2 x )}{53} + \frac{7 e ^{7 x} cos ( 2 x )}{53} + C

Solution steps

\int e^{7 x} cos (2 x) d x

Apply Integration By Parts

= \frac{1}{2} e^{7 x} sin (2 x) - \int \frac{7}{2} e^{7 x} sin (2 x) d x

Take the constant out:

\int a \cdot f (x) d x = a \cdot \int f (x) d x

= \frac{1}{2} e^{7 x} sin (2 x) - \frac{7}{2} \cdot \int e^{7 x} sin (2 x) d x

Apply Integration By Parts

= \frac{1}{2} e^{7 x} sin (2 x) - \frac{7}{2} (- \frac{1}{2} e^{7 x} cos (2 x) - \int - \frac{7}{2} e^{7 x} cos (2 x) d x)

Take the constant out:

\int a \cdot f (x) d x = a \cdot \int f (x) d x

= \frac{1}{2} e^{7 x} sin (2 x) - \frac{7}{2} (- \frac{1}{2} e^{7 x} cos (2 x) - (- \frac{7}{2} \cdot \int e^{7 x} cos (2 x) d x))

Therefore

\int e^{7 x} cos (2 x) d x = \frac{1}{2} e^{7 x} sin (2 x) - \frac{7}{2} (- \frac{1}{2} e^{7 x} cos (2 x) - (- \frac{7}{2} \cdot \int e^{7 x} cos (2 x) d x))

Isolate

\int e^{7 x} cos (2 x) d x

= \frac{2 e ^{7 x} sin ( 2 x )}{53} + \frac{7 e ^{7 x} cos ( 2 x )}{53}

Add a constant to the solution

= \frac{2 e ^{7 x} sin ( 2 x )}{53} + \frac{7 e ^{7 x} cos ( 2 x )}{53} + C

What is the integral of e^{7x}cos(2x) ?
The integral of e^{7x}cos(2x) is (2e^{7x}sin(2x))/(53)+(7e^{7x}cos(2x))/(53)+C