Sử dụng phần mềm Geometer's sketchpad trong quá trình dạy học môn Toán ở trường cao đẳng sư phạm

SITDUNG PHAN MEM GEOMETER'S SKETCHPAD

IRONG QUA TRlNH DAY HOC MllN TOAN1} TR M CAO BANG Sir PHAM

Q ThS. BOlTHj THANH THU V

Hidn nay, vide Ong dyng cdng ngh| thdng

Hn vdo qud trinh dqy hqe Id mdt vide ldm

tdt ylu. Geometers Sketchpad (Htudng

duqc gqi tdt Id Skechpod hoy GSR) Id phdn mIm

eho phdp tqo ro cdc hinh hlnh hqc odng Hong

qud trlnn dqy hqc todn. Uu dilm k5n nhdt cOa

GSP Id d l cdl ddt, d l su dyng ndn phdn mIm

ndy phd dyng hon so vdi cdc phdn mIm cOng

k>qi khdc nhu: PowerPoint, CabrI GeomeHy,...

Trong chuong hinh ddo h ^ d cdc trudng coo

ddng su phqm (COSP), nlu gidng vidn (GV)

thudng xuydn GSP Hong qud Hinh oqy hqc mdn

Todn sd glOp sinh vidn (SV) Hip cdn duqc vdl cdc

phdn mIm dqy hqc, ddng thdi rdn luy$n eho SV

kr ndng su dyng cdng nghe thdng Hn trong qud

Hinh hqc tdp cung nhu Hong cdng h^c gidng oqy

sou ndy. Eidl vllt duo ra mdt sd vf dy v l vide sO

dyng phdn mIm GSP trong dqy hqc cdc hqc phdn

thudc bd mdn Todn d Hudng CDSP.

Vr</y J: Cho dudng Hdn (O, R) vd dilm A d

ngodi dudng trdn. Gqi d Id dudng thdng vudng

gdc vdl OA tqi A. Gqi M Id mqt diem trdn d. Tu

M ve hal Hip hjyIn MT, MT' cuo (O, R). Ddy TT'

cdt O M Iql N. Tim quy h'ch dilm N khi M dl ddng

Hdn d (/i/n/i 7).

Hinh I

Bdi todn tim quy Hch Id mdt bdi lodn khd. Dilm

khd nhdt cOo bdl todn 77m auy tfch Id vide dy

dodn quy h'ch. Nlu gldl quylt bdl todn md khdng

Tgp Chi Slao due s6 284 (ki a - 4/aoia)

su dyng GSP ngudi hqc ddl khi phdl vd mdt sd v|

H( cuo dilm dl ddng d l h> dd dy dodn quy Hch

vd djnh hudng vide chqn phuong phdp gldl (khd

md't thdi glon vd ddl khi khdng chinh xdc). Nlu

sO dyng GSP d vf dy ndy, ta cd thi th ^ ngoy

qu^ Hch dilm N.

D l Hm quy Hch dilm N, Hi cdn riiyc hiln mdt

sd riioo h^e dyng hinh sou: + Dyng dudng vudng

gdc vdi OA tqi A (phdn mIm dd cd s5n cdng ey

d l dyng); + Dyng hoi Hip hryln cOa (O; R) cOng

xudt phdt tu dilm M (pndn mIm khdng cd sdn,

khi dd ngudi vd edn suy ludn duqe hal t\ip dilm

T, T' thudc dudng Hdn dudng kinh OM . TO dd T,

T' Id gioo cuo dudng trdn dudng kfnh O M vd

dudng h^n (O, R)); + Dyng gioo dilm N cOo TT

vdOM .

Khi dd dyng xong hinh, to tqo vlt cho N (chqn

dilm, CH + T), cho dilm M ehqy h ^ d (chqn

dilm, Alt + ') thi N sd qudt ro mdt dudng hdn,

nghTo Id quy tich cuo dilm N Id dudng Hdn, h>

dd ngudi hqe Hm duqc djnh hudng gldl odi todn.

idil dqy hqc gidi bdl tdp hinh hqc hay v i nhOng

hinh phuc h;ip, vide vd hinh Id rdt quon Hqng, bdi

hinh vd cdng trye quon thi vide ^nh hudng d l

chOng minh cdng d l ddng. GSP ed cdng ey di

chuyin dilm, dudng thdng ndn khi dOng phdn

mIm ndy to cd thi vd hinh rdt nhanh vd dl ^uyl n

cdc ddi tuqnQ 64 hinh vd d l nhin. Nlu mdt bdi

tdp cd nhllu edu hdl, la (^ Hil copy phdn hlnh

eho Khig cdu hoy dn bdt nhOng ddi tuqng khdng

lidn quon din cdu hdl d l gldl quvlt vdn d l (nlu

dOng bdng phdn khi cdn pfidl vd Iql hlnh khdc sd

rdt mdt Hidl glon).

Wt^V 2: Veellp(E)ed phuong hrinh j+^=i

Phdn mIm GSP khdng cd sdn cdng cy ve elip

nhu v8 dudng frdn. Vi vdy, d l vd duqc ehlnh xdc

ellp cdn phdl sO dyng cdng thOc ddl h$ tqo dd

* Tnrtii 1 ^ diig s« pbMiKM Bjik

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