In triangleabc, c is the right angle. if tana = 8/6, find cosb

a. 6/8
b. 6/10
c. 8/10
d. doesnt exist

Short answer = C) 8/10

Working :

Tan A = 8/6 = Opposite / AdjacentOpposite = 8 units

Adjacent = 6 units

Hypotenuse =

                     =

                     =

                     = 10 units

Cos B  = Adjacent/ Hypotenuse

        ∴  cos B= 8/10

Of course many things may be said about the function f(x) = - √x, so for a specific answer you need to add the list of choices to select the right statement.anyhow, i can you by highlighting many facts of the function - √x, that for sure will you: 1) the paren function of -√x is √x (that means that the graph of the function -√x is obtained from the graph √x with a simple transformation).2) the domain of - √x is the same domain of its parents function, and that is all the positive real values [0, ∞)3) the range of - √x is all the negative real values: y ≤ 0 or (-∞,0].4) the function -√x is strictly decreasing and its graph is in the fourth quadrant (this is neative-y and positive-x).5) the function -√x is the result of reflecting the parent function, √x, across the x-axis.6) you can see attached the graph of thw two functions -√x and √x, so that you can grasp all the information better.the blue curve is the function -√x, the red line is the function √x.