A composition of 300 words about helping mother do housework

A composition of 300 words about helping mother do housework

Help mother do housework 300 words

This morning, mom and dad went to work, leaving me at home alone. I had breakfast and put the bowls in the pot. At this time, I saw many bowls in the pot. I thought it must be Mom and dad who were in a hurry to go to work and didn't have time to wash the dishes, so I put them there to wash after I got home from work

It is proved that there is no real number root for the equation of half X & # 178; + (M + 1) x + M & # 178; + m + 1 = 0

Discriminant △ = (M + 1) &# 178; - 4 * 1 / 2 * (M & # 178; + m + 1)
=m²+2m+1-2m²-2m-2
=-m²-1

A. B and C are three points in the coordinate plane, O. if the projection of vectors OA and ob on OC is the same, what formula does a and B satisfy?
(OA · OC) / | OC | = (OB · OC) / | OC |, what do you mean?

The projection of vector OA and ob in OC direction is the same
(OA · OC) / | OC | = (OB · OC) / | OC | (this is a conceptual problem)
So OA · OC = ob · OC
4a+5=8+5b
There is 4a-5b = 3

A mathematical problem, on the polynomial
If the second power of 2N-1 power y of - 1 / 3x is the same as the second power of octave y of 3x, find the value of power 2003 of algebraic formula (1-N) multiplied by power 2003 of (n-59 / 14)

The second power of 2N-1 power y of - 1 / 3x is the same as the second power of octave power y of 3x
The 2N-1 power of x = the octave power of X, n = 4.5
The original formula = (1-4.5) to the power of 2003 × (4.5-59 / 14) to the power of 2003
=2003 power of (- 7 / 2) × 2003 power of 2 / 7
=-1

Let m be the midpoint of AA 'in the cube ABCD-A ′ B ′ C ′ d' with edge length 1, then the cosine of the angle formed by the line cm and D ′ D is___ ．

As shown in the figure: ∵ D ′ D ∥ AA ′, ∥ CMA is the angle formed by the out of plane straight line cm and D ′ D. in RT △ Mac, ∥ MAC = 90 °, am = 12aa ′ = 12, AC = 2, ∥ cm = ma2 + ac2 = 14 + 2 = 32 ∥ cos ∥ CMA = MAMC = 1232 = 13 ∥ the cosine value of the angle formed by the straight line cm and D ′ D is 13, so the answer is 13

A plus B minus the square of C

(a+b-c)²=[(a+b)-c]²
=(a + b) & # 178; - 2 (a + b) C + C & # 178; [i.e., regard (a + b) as a whole]
=a²+2ab+b²-2ac-2bc+c²
=a²+b²+c²+2ab-2ac-2bc

It is known that M is the midpoint of line AB and P is any point on line BM. PM = half (pa-pb)

Proof: a-m-p-b
∵ m is the midpoint of ab
∴AM＝BM＝AB/2
∵PA＝AM+PM
PB＝BM-PM
∴PA-PB＝AM+PM-（BM-PM）＝AM+PM-BM+PM＝（AM-BM）+2PM＝2PM
∴PM＝（PA-PB）/2

3x-20 / 5 = 1x + 20 / 4

3x-4x = 20 + 20
7x of 20 = 40
X = 800 out of 7

If the radius of the bottom of the cone is 2 cm and the length of the generatrix is 4 cm, then the side area of the cone is 2 cm______ Cm 2 (π is reserved for the results)

If the radius of the bottom circle is 2, the perimeter of the bottom is 4 π and the side area is 12 × 4 π × 4 = 8 π cm2