Let X be greater than or equal to 2, then what is the minimum value of the function y = [(x + 5) (x + 2)] / 2?

Let X be greater than or equal to 2, then what is the minimum value of the function y = [(x + 5) (x + 2)] / 2?

x>=2
y=[(x+5)(x+2)]/2
=(x²+7x+10)/2
=[(x+7/2)²-9/4]/2
When x = 2, the minimum value of y = [(2 + 7 / 2) & sup2; - 9 / 4] / 2 = 14

The minimum value of function y = x ^ 4 / 4 + x ^ 3 / 3 + x ^ 2 / 2 on [- 1,1] is?

Y '= x ^ 3 + x ^ 2 + x = x (x ^ 2 + X + 1) = x [(x + 1 / 2) ^ 2 + 3 / 4]
When x = 0, y '= 0, y has the extremum

The minimum value of function y = 1 / 4 x ^ 4 + 1 / 3 x ^ 3 + 1 / 2 x ^ 2 on [- 1, - 1] is?

First, the derivative of Y is the third power of X + the square of X + X. let the formula be 0, then the value of X is 0, so there is a minimum value of 0 at 0