Explain how to solve: cos(arcsin√5/3)
In cases like this, always draw the triangle involved. You want cosx, where sinx = √5/3
So, the hypotenuse is 3, and the opposite leg is √5
The near leg is √(3^2-5) = √4 = 2
so, cosx = 2/3
So, the hypotenuse is 3, and the opposite leg is √5
The near leg is √(3^2-5) = √4 = 2
so, cosx = 2/3