The side length of square ABCD is 5, P is a moving point on the side of BC, let Pb be x, the functional relationship between the area of triangle PCD y and X is - the value of X is

The side length of square ABCD is 5, P is a moving point on the side of BC, let Pb be x, the functional relationship between the area of triangle PCD y and X is - the value of X is

Y=1/2 * CD * PC
=1/2 * 5 * (5-X)
=-5X/2 + 25/2
The value range of x [0,5]

Inequality. The perimeter of a right triangle is l, find the maximum area

Let a ^ 2 + B ^ 2 = C ^ 2, because a + B + C = L = a + B + (a ^ 2 + B ^ 2) ^ (1 / 2) ≥ 2 (AB) ^ (1 / 2) + (2Ab) ^ (1 / 2) = (2 + √ 2) (AB) ^ (1 / 2), so ab ≤ [(3-2 √ 2) / 2] * L ^ 2S = AB / 2, the maximum value is [(3-2 √ 2) / 4] * L ^ 2. Use trigonometric function to do: let the hypotenuse of △

The perimeter 2p of a right triangle is used to find the maximum area

The biggest is the isosceles right triangle, which is x + X + radical 2 * x = 2p
Then p is used to express X
Then s = 1 / 2x squared~