An airplane flies at an altitude of 6 miles toward a point directly over an observer. Consider θ and x as shown in the figure. (a) Write θ as a function of x. θ = (b) Find θ when x = 15 miles and x = 3 miles. (Enter your answers in radians rounded to two decimal places.) x = 15 miles θ ≈x = 3 miles θ ≈