How do you simplify the expression cos[arcsin(x)]sin[arccos(x)]?

1 Answer
Oct 10, 2016

cos(arcsin(x))sin(arccos(x))=1x2

Explanation:

Let's draw a right triangle.

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In this triangle, we've chosen a leg of length x and a hypotenuse of length 1, meaning sin(a)=cos(b)=x1=x. Because of that, we know that a=arcsin(x) and b=arccos(x). Additionally, we can use the Pythagorean theorem to find the length of the remaining leg as 1x2

We can now use this triangle to find the product.

cos(arcsin(x))sin(arccos(x))=cos(a)sin(b)

=1x211x21

=1x2