Given that the two extreme points of the function f (x) = ax ^ 3 + BX ^ 2 + CX + D are - 1 and 3, and f (0) = - 7, f '(0) = - 18, find the expression of F (x)

Given that the two extreme points of the function f (x) = ax ^ 3 + BX ^ 2 + CX + D are - 1 and 3, and f (0) = - 7, f '(0) = - 18, find the expression of F (x)

f(0) = d = -7
f'(x) = 3ax² + 2bx + c
f'(0) = c = -18
f'(-1) = 3a - 2b - 18 = 0
f'(3) = 27a + 6b -18 = 0
a = 2,b = -6
y = 2x³ - 6x² - 18x - 7

If the odd function f (x) = AX3 + bx2 + CX has an extreme value at x = 1, then 3A + B + C =?

Odd function: F (x) = f (- x), so B = 0
F (x) 'is 3x2 + B + C, that is, 3ax2 + C
And f (1) '= 0, so 3A + C = 0
3a+b+c=0

Why is the zero power of 2 equal to 1
The reason must be given accurately

Except that the power 0 of 0 is meaningless, the power 0 of any number is equal to 1

Any rational number can be expressed as a point on the number axis. Conversely, any point on the number axis can be expressed as the value of a rational number, right
How can irrational numbers be represented on the number axis

Wrong
Any point on the number axis can be expressed as a real number

Function f (x) = CX + D / ax + B on point P_________________ symmetric.
Explain as much as you can~

P(-b/a,c/a)

Is the predicate of more than one book singular or plural?

More than one person is involved in this. If things don't get better, more than one person is goi

As shown in the figure, ∠ B = 90 °, ab = 6, BC = 8 in △ ABC, fold △ ABC along de so that point C falls at C ′ on the edge of AB, and C ′ D ‖ BC, then the length of CD is ()
A. 409B. 509C. 154D. 254

Let CD = x, according to C ′ D ‖ BC and C ′ d = EC, we can get that the quadrilateral C ′ DCE is rhombic; that is, in RT △ ABC, AC = 62 + 82 = 10, be8 = C ′ E10 = CD10 = X10, EB = 45x; therefore, we can get BC = x + 45x = 8; the solution is x = 409

English phrases and usages expressing many and many meanings

A lot of or lots of (+ countable C / uncountable U) a (great / large) number of + (c) a (great / large) amount of + (UN)!

1988+1989×19871988×1989−1=______ ．

1988 + 1989 × 19871988 × 1989 − 1, = 1988 + 1989 × (1988 − 1) 1988 × 1989 − 1, = 1988 + 1989 × 1988 − 19891988 × 1989 − 1, = 1988 × 1989 − 11988 × 1989 − 1, = 1

Eating out of your hands.

Eat out of sb's hand means to listen to someone, eat out of your hands means to listen to you