Suppose x=9 tan (theta) and the angle (theta) is in the first quadrant. Write algebraic expressions for sin (theta) and cos (theta) and in terms of x.

The tangent trigonometric function is equal to the quotient of sine and cosine through the trigonometric identity. In this case, we are given with x = 9 tan (theta). Hence the answer to this problem is the expounded algebraic expression x = 9 sin (theta) / cos (theta).