The absolute value of negative a is equal to negative a if

The absolute value of negative a is equal to negative a if

-|If a | = - A, then a ≥ 0
|-If a | = - A, then a ≤ 0

Given that the points a (1, Y1), B (2, Y2), C (3, Y3) are on the parabola y = 5x & # 178; + 12x, then the area of △ ABC is____ .

y1 = 5 *1² + 12 * 1 = 17
y2 = 5 *2² + 12 * 2 = 44
y3 = 5 *3² + 12 * 3 = 81
BC line k = (81-44) / (3-2) = 37
y-81 = 　37 (x - 3)
BC line intersects y = 17 line, intersection P
y-81 = 　37 (x - 3)　
y = 17
X = 3-64 / 37
Intersection P (3-64 / 37, 17)
BP = 3-64/37 -1 = 2-64/37
Area of ABC = area of APC - area of BPC = 1 / 2 * BP * (81-17) - 1 / 2 * BP * (44-17)

The problem of finding function derivative image in MATLAB
Function I1 = illbird (T, I1)%
k1=0.5;
I1=(k1*I1*(1-I1))';
day=0:50;
I10=0.002;
[t,I1]=ode45('illbird',day,I10);[t,I1]
plot(t,I1),grid,pause
dI1=diff(I1)
plot(t,dI1),grid
Only one picture came out. Why?
error
Error using ==> plot
Vectors must be the same lengths.

Let's give some examples of the functions f (AB) = f (a) + F (b) and f (a + b) = f (a) * f (b), and discuss their common properties respectively. Let's give more examples

f(ab)=f(a)+f(b)
Logarithmic function
y=log2(x).y=log(0.5)(x) y=lgx,y=lnx
Over (1,0), domain (0, + ∞), range y ∈ R
f(a+b)=f(a)*f(b)
exponential function
y=2^x.y=3^x ,y=4^x
The over (0,1) domain is r, and the value domain is (0, + ∞)

It is known that the power a of 4.25 is equal to 1000, and the power B of 0.000425 is equal to 1000. Find the value of the algebraic formula 1 / A-1 / b
Hurry up, I'm going to, and there's something to add when it's done

The two formulas can be reduced to: lg4.25 ^ a = lg1000, alg4.25 = 3; lg0.000425 ^ B = lg1000, B (- 4 + lg4.25) = 3;
1/a-1/b=（lg4.25）/3-(-4+lg4.25)/3=4/3

"Some rational numbers can't be expressed on the number axis", right? For example, please~

It's not right
The points on the number axis represent all the real numbers
And rational numbers are real numbers, so rational numbers can be expressed on the number axis
It's all in the books

How to find the axis of symmetry for the function image of form ax + B / CX + D

x=-(b/c)/(2a)=-b/(2ac)

More students than one, singular or plural?

Use the plural. The central word here is students.than It's just a preposition, and that one is just a preposition phrase

In the triangle ABC, the angle c = 90, AB: BC = 5:3, AC = 8

Triangle ABC middle angle c = 90 degree AB: BC = 5:3 AC = 8
So BC = 6

Special usages and phrases of English words related to color
Green hand is a novice

Be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red be in the red Red tape red tape red tape