A curve is given parametrically by the equations x = 2 cos t + cos 2t, y = 2 sin t – sin 2t. Show that the gradient of the curve at the point with
parameter t is - tan(1/2)(t)

The construction of copying qpr is started below. the next step is to set the width of the compass to the length of ab. how does this step ensure that a new angle will be congruent to the original angle? by using compass take the measures of angle and draw the same arc according to it.