angle B is acute and sinB = 1/3. What is the exact value of the cosine of this angle?
Draw a right angled triangle.
Label one accute angle as B
Sin B is 1/3 so label the opposite side as 1 and the hypotenuse as 3
Use the pythagorean theorum to find the exact length of the third side.
Now read Cos B directly of your diagram
