Let the parabola y = 4-x & # 178; the intersection point of the parabola y = 3x and the straight line y = 3x be A.B, and the point P moves from a to B on the parabola. (1) find the area of the triangle PAB to be the largest Let y = 4-x & # 178 be A.B. point P moves from a to B on the parabola (1) Find the coordinates of point P when the area of △ PAB is the largest (2) It is proved that the figure enclosed by parabola y = 4-x and line y = 3x is divided into two parts with equal area by line x = a (1) Find the coordinates of point P when the area of △ PAB is the largest. And find out the maximum area 2. Let the straight line y = 2x + B and the parabola y & # 178; = 4x intersect at two points a and B, and the length of the chord AB is 3 √ 5, then calculate the area of △ AOB

Let the parabola y = 4-x & # 178; the intersection point of the parabola y = 3x and the straight line y = 3x be A.B, and the point P moves from a to B on the parabola. (1) find the area of the triangle PAB to be the largest Let y = 4-x & # 178 be A.B. point P moves from a to B on the parabola (1) Find the coordinates of point P when the area of △ PAB is the largest (2) It is proved that the figure enclosed by parabola y = 4-x and line y = 3x is divided into two parts with equal area by line x = a (1) Find the coordinates of point P when the area of △ PAB is the largest. And find out the maximum area 2. Let the straight line y = 2x + B and the parabola y & # 178; = 4x intersect at two points a and B, and the length of the chord AB is 3 √ 5, then calculate the area of △ AOB

Supplementary question 2,
The length of AB is the expression of B. the value of B can be obtained,
The distance from point O to the straight line y = 2x + B can be obtained by the distance between two straight lines y = 2x and y = 2x + B. the distance from the long x point O to the straight line with area = 1 / 2xab can be obtained