As shown in the figure, in the isosceles triangle ABC, ∠ B = 90, ab = BC = 4cm, point P moves from point a to B at the speed of 1m / s, At the same time, point Q moves from point B to point C at a speed of 2 m / s (1) Which point will arrive first? (2) Let the area of triangle ACB be Y1 and the area of triangle qAB be Y2 after X minutes (3) When the moving time is in what range: (1) the area of triangle PCB is larger than that of triangle; (2) the area of triangle PCB is smaller than that of triangle qAB? Picture too late to pass, sorry!

As shown in the figure, in the isosceles triangle ABC, ∠ B = 90, ab = BC = 4cm, point P moves from point a to B at the speed of 1m / s, At the same time, point Q moves from point B to point C at a speed of 2 m / s (1) Which point will arrive first? (2) Let the area of triangle ACB be Y1 and the area of triangle qAB be Y2 after X minutes (3) When the moving time is in what range: (1) the area of triangle PCB is larger than that of triangle; (2) the area of triangle PCB is smaller than that of triangle qAB? Picture too late to pass, sorry!

(1) The topic gives the motion time X minutes, gives their respective motion speed, can find out the size of the line, and then use the area formula of right triangle to write the functional relationship; (2) from (1) know their respective analytical formula, according to the topic meaning area is equal, list the equation, through solving the equation can get the answer; (3) according to