Let y=2x2+4x+5.
(i) Show that the quadratic equation 2x2+4x+5=0 has no real roots.
(ii) Find the y-intercept of the graph.
(iii) Calculate the value of the polynomial at x=−1 and plot the three points obtained so far.
(iv) Sketch the graph of the polynomial, clearly indicating its position with respect to the x-axis.