What is the integral of sin(105x)sin(45x) ?

The integral of sin(105x)sin(45x) is 1/2 (-1/150 sin(150x)+1/60 sin(60x))+C

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integral of sin(105x)sin(45x)

\int sin (105 x) sin (45 x) d x

\frac{1}{2} (- \frac{1}{150} sin (150 x) + \frac{1}{60} sin (60 x)) + C

Solution steps

\int sin (105 x) sin (45 x) d x

Rewrite using trig identities

= \int \frac{1}{2} (- cos (150 x) + cos (60 x)) d x

Take the constant out:

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

= \frac{1}{2} \cdot \int - cos (150 x) + cos (60 x) d x

Apply the Sum Rule:

\int f (x) \pm g (x) d x = \int f (x) d x \pm \int g (x) d x

= \frac{1}{2} (- \int cos (150 x) d x + \int cos (60 x) d x)

\int cos (150 x) d x = \frac{1}{150} sin (150 x)

\int cos (60 x) d x = \frac{1}{60} sin (60 x)

= \frac{1}{2} (- \frac{1}{150} sin (150 x) + \frac{1}{60} sin (60 x))

Add a constant to the solution

= \frac{1}{2} (- \frac{1}{150} sin (150 x) + \frac{1}{60} sin (60 x)) + C

What is the integral of sin(105x)sin(45x) ?
The integral of sin(105x)sin(45x) is 1/2 (-1/150 sin(150x)+1/60 sin(60x))+C