Eric Hauschild — Teaching Journal Pages, 1979-2014

3 / 14 / 79 (Wed.)

y = (x-2)(x+3)

Algebra II — Per. 3 & 5

Factoring polynomials (cont.)

Warm-up: x² − 5x + 6, x² + x − 12, 2x² − 7x + 3. Two min. silent, then walk it.

Difference of squares — a² − b² = (a−b)(a+b). Karen S. needs the geometric picture again.

§4.6 — 1, 5, 9, 13, 17, 21
§4.7 — evens, 2 to 18
Challenge: factor x⁴ + 4

Quiz Friday — 4 problems.

Wed night strange — woke 3am, nosebleed both sides? right only. Small dried spot inside the right nostril when I checked at the mirror. Dog on the porch — would not come in past the screen door, just sat. Slept on the couch the rest. Lillian thinks I'm tired. Maybe.

Oct. 2, 1986

∫

(out window)

Calculus II — 1st per.

Derivative of arctan

d/dx [ arctan x ] = 1 / (1 + x²)

Implicit derivation. Let y = arctan x, so tan y = x:

sec²(y) · dy/dx = 1
dy/dx = cos²(y)
right triangle: opp=x, adj=1, hyp=√(1+x²)
∴ dy/dx = 1/(1 + x²) ✓

Make them draw the triangle. The triangle is the thing.

HW: §6.4 odds, 1–25. Skip 19 (typo).

Sat night gone again. Lillian says I was at the kitchen 12:30 — I have no memory after 11:15. Looked at clock kitchen — 3:17. Two hours and one minute is the gap I cannot fill in. The lawn looked wrong on Sunday. Took it to two coats of memory before I could replace what I lost. The dog spent Sunday in the front room with her face to the wall.

Nov. 7, 1993 — Sun.

A+C = B+D = π

Geometry — Mon. plan

Cyclic quadrilaterals — opp. angles supp.

Thm: ABCD inscribed in a circle ⟹ ∠A + ∠C = 180°.

Proof (inscribed-angle):

∠A subtends arc BCD; ∠C subtends arc BAD.
Inscribed angle = ½ central, so
∠A + ∠C = ½·arc(BCD) + ½·arc(BAD) = ½(360°) = 180°. ∎

Let them try the converse for hwk. Tom L. will see it first; let him.

§10.3 — 4, 7, 11, 12, 18.

Cycle.

I have a word for it now. The word came in a dream. I do not know who gave me the word. It feels like a word someone else taught me. Every seven years is the cycle. I have been counting. I can count back to 1965 if I am careful. I am 46. I started, I think, at nine — or ten, or eleven; the cycle is on me but the first-iteration date is not.

1963 — 1970 — 1977 — 1984 — 1991 (this past Sept., I think). The next will be 1998.

The figure on the road in the dreams is always the same. Long arms. It does not move toward me. I move toward it.

Sept. 22, 2007

— the dream again

AP Calc AB — Final Blueprint

40 MC / 6 FR. 3h 15m.

Coverage

Limits & continuity — 10%
Derivatives (rules, implicit) — 25%
Applications (related rates, MVT) — 20%
Integrals (FTC, u-sub) — 25%
Slope fields — 10%
Particle motion — 10%

FR: one related rates, one accumulation, one slope field, one v/a, one area & volume.

No L'Hôpital — moved to BC. Tell them anyway.

Marina visited last weekend. Did not tell her. Will not tell her. Lillian would have told her. Lillian would have asked the right questions.

The next one is, by my count, this autumn. I have left the porch light off. The dog (Pepper now, the second Pepper) has been quiet but watchful. I wonder if dogs know it the way I have learned to know it — by something just outside the eye.

I am sixty. I have lived through eight of these, if I count correctly from 1956. I think I count correctly.

5 / 14 / 14

I have remembered the procedure for the first time. I will not write it down. It is enough that I have remembered.

The next one is in 2019. Marina turns 38 this year. She does not know. I will not tell her until I cannot.

Eric Hauschild — Teaching Journal Pages, 1979-2014

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