# Math Help - Help In Calculus Needed

1. ## Help In Calculus Needed

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2. Originally Posted by frozenflames
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Hello,

you have to find $\int {sin(x) \cdot cos(y)\ dx$

Substitute $u=sin(x)\ \Longrightarrow \ \frac{du}{dx}=cos(x)\ \Longrightarrow \ du=cos(x) \cdot dx$

The integral is now $\int {u \cdot du}=\frac{1}{2}(u)^2+c$

Re-substitute and you'll get: $\int {sin(x) \cdot cos(y)\ dx=\frac{1}{2}(sin(x))^2+c$