1.What is the natural domain of the function f(x) = 2x -1?a.All of the real numbersb.X = 0.5c.All real numbers except x = 0.5d.All positive real numbers2.Suppose f(x) = x^2 + 1 (Note that ^ is the power of function; x^2 represents x squared) Whicch one of the following represents f(f(x))?a.f(f(x)) = (x^2 + 1)^2 +1b.f(f(x)) = (x^2 +1)^2c.f(f(x)) = x^4 + 2x^2 + 1d.f(f(X)) = x^4 + 13.Consider the following unit circle.Which one of the following is FALSE?a.y 0 = sin (T)b.x 0 = cos(t)c.cos(-t) = cos(t)d.sin(-t) = sin(t)4.The matlab command for finding the limit of an expression y as x tends to c is: >> limit(yxc)Matlab uses Nan to say a limit does not exist and Inf to say a limit is infinity. The Matlab function for absolute value is abs(x); this gives IxI.a.0b.Infc.NaNd.15.A piecewise function f is defined by:F(x) = x + k when x is less than 1 andF(x) = 3 otherwise.What value of k makes f continuous at x =1?a.1b.No value of kc.3d.2