Help me translate the Chinese meaning of the following sentences. Thank you Maybe you do not know ,you are my first boyfriend in this life.

Help me translate the Chinese meaning of the following sentences. Thank you Maybe you do not know ,you are my first boyfriend in this life.

FORTRAN statement
What does format ((f7.2,2x)) mean?

Suppose the current value of the M variable is 5
It is equivalent to 5 (f7.2,2x)
This usage is only an extension of some compilers, not a standard usage

If the circumference of a rectangle is (4a + 2b) and its width is (a-b), then its length is ()
A. a+2bB. aC. 3a+3bD. 3a+b

According to the meaning of the question: 12 (4a + 2b) - (a-b) = 2A + B-A + B = a + 2B

If AB = 8, the chord center distance of AB is 3, then the length of PA is ()
A. 5B. 203C. 253D. 8

As shown in the figure: connecting OA, ob, ∵ PA, Pb is the tangent line of ⊙ o, ∵ OA ⊥ AP, ob ⊥ BP, PA = Pb, so PC ⊥ AB, AC = BC = 12ab = 12 × 8 = 4cm, OC = 3cm. According to Pythagorean theorem, OA = ac2 + oc2 = 42 + 32 = 5cm, ∵ {1 +} 2 = 90 °, ∵ 2 +} OAB = 90 ° and ∵ OAB = 1

In triangle MPN, h is the intersection of high MQ and NR, Mr = NR, HM = PN

∵ RT △ PNR, ∠ PNR + ∠ RPN = 90 degrees
RT △ PMQ, ∠ HMR + ∠ RPN = 90 degrees
∴∠PNR=∠HMR
In RT △ PNR and RT △ HMR, Mr = NR, ∠ PNR = ∠ HMR
∴Rt△PNR ≌ Rt△HMR
∴HM=PN

The diagonals AC and BD of rectangle ABCD intersect at O, make ef through O, perpendicular to AC, intersect ad at F, BC at e, ab = 2, BC = 4, and calculate the area of aecf

In the figure, because AC is perpendicular to EF and AF is parallel to EC, the quadrilateral aecf is rhombic, ab = 2, BC = 4, so AC = 2sqrt (5), OC = sqrt (5), △ ACB ≌ △ Eco, so AB / BC = EO / OC, OE = sqrt (5) / 2, aecf area is 5

Z1 = (1-I) quartic power + (2 / (1 + I)) is the equation x & # 178; + PX + q = 0, P + Q=

z1=(1-i)^4+2/(1+i)=-3-i
Because the imaginary roots appear in pairs and conjugate with each other, the other root is Z2 = - 3 + I
So according to Weida's theorem
z1+z2=-p=-6
z1*z2=q=10
So p + q = 16

Let the moving line l be perpendicular to the X axis and intersect with the ellipse X & # 178; + 2Y & # 178; = 4 at two points a and B, p be the point on L, and PA vector × Pb vector = 1, then the trajectory equation of P point is obtained

Let P (x, y) a (x, Y1) B (x, Y2) vector PA = (0, y1-y) vector Pb = (0, y2-y) (y1-y) (y2-y) = 1y1 * Y2 - (Y1 + Y2) Y-Y ^ 2 = 1 (Y1 + Y2) = 0, the formula is: Y1 * y2-y ^ 2 = 1Y2 = - Y1, the formula is: - Y1 ^ 2-y ^ 2 = 1a (x, Y1) on the ellipse, so, x ^ 2 + 2y1 ^ 2 = 4 in - Y1 ^ 2-y ^ 2 = 1, both sides are multiplied by 2

Given X3 + x2 + X + 1 = 0, find the value of 1 + X + x2 + X3 + X4

1 + X + x2 + X3 + X4 = 1 + X (X3 + x2 + X + 1), and ∵ X3 + x2 + X + 1 = 0, the original formula = 1 + X × 0 = 1

Abcd-a1b1c1d1 is a parallelepiped. Let AB = a, ad = B, Aa1 = C, e and f be the midpoint of AD1 and BD respectively, then EF =?
AB, ad, Aa1, EF are vectors

This problem can be done with the definition of vector,
There are mainly two knowledge points: 1
The diagonals of parallelograms are bisected
Make auxiliary line, connect AC, and intersect BD at point F '
Because the diagonals of parallelograms are equally divided
So f 'divides BD equally
That is, point F coincides with point F ', and point F bisects AC
It is known that ab = a, ad = B, Aa1 = C
Then d1a1 = - B A1A = - C ad = B DC = a
Then EF = EA + AF
=1/2D1A+1/2AC
=1/2(D1A1+A1A)+1/2(AD+DC)
=1/2(-b-c)+1/2(b+a)
=1/2(a-c)