In circle k(O), AC is a diameter, AB is a chord, and MA is tangent to the circle. Angle ∠MAB is acute. Prove that m∠MAB=m∠ACB.

answer: domain and range mean all possible values of x and y that could be substituted to the inequality. a solution means all possible values that make the inequality statement true. so while the range is still all real numbers, the solution is the shaded area, for which y will always be greater than the line of the function.