PRESENT TIME (bagian 1)

Simple Present

a)      Ann takes a shower every day.

b)      I usually eat lunch at the cafeteria.

c)       Babies cry.

d)      The earth revolves around the sun.

e)      A square has four equal sides.

f)       The sky is blue.

 

The simple present expresses daily habits or usual activities, as in (a) and (b).

The simple present expresses general statements of fact, as in (c) and (d). In sum, the simple present is used for events or situations that exist always, usually, or habitually in the past, present, and future.

Present Progressive

a)    Ann can’t come to the phone right now because she is taking a shower.

b)   It’s noon. I am eating lunch at the cafeteria right now.

c)    Jimmy and Susie are babies. They are crying. I can hear them right now. Maybe they are hungry.

The present progressive expresses an activity that is in progress (is occuring, is happening) right now. The event is in progress at the time the speaker is saying the sentence. The event began in the past, is in progress now, and will probably continue into the future.

FORM : am, is, are + -ing.

 

Bentuk-bentuk Simple Present dan Present Progressive

1. Statement

Simple Present                                 :

{ I-You-We-They } work.

{He-She-It} works.

 

Present Progressive       :

I am working.

{You-We-They} are working.

{He-She-It} is working.

 

1. Negative

Simple Present                                 :

{ I-You-We-They } do     not work.

{He-She-It} does             not work.

 

Present Progressive       :

I am      not working.

{You-We-They} are         not working.

{He-She-It} is    not working.

 

1. Question

Simple Present                                 :

Do { I-You-We-They }  work?

Does         {He-She-It}   work?

 

Present Progressive       :

Am         I                                working?

Are {You-We-They}         working?

Is  {He-She-It}                   working?

(Sumber : Azar, B.S., 1993, Fundamentals of English Grammar, Edisi Dwibahasa, Binarupa Aksara, Jakarta)

FUNGSI

Variabel  adalah simbol yang dipilih untuk menyatakan sebarang bilangan dalam suatu himpunan bilangan (asumsi : bilangan real) yang diketahui . Jika himpunan tersebut hanya terdiri dari satu bilangan, maka simbol yang direpresentasikannya disebut konstanta.

Range dari suatu variabel terdiri dari seluruh bilangan dari himpunan yang merepresentasikannya.

Fungsi  : Suatu korespondensi (x, y) antara dua himpunan bilangan yang memasangkan sebarang bilangan x dari himpunan pertama dengan tepat satu bilangan y dari himpunan kedua disebut suatu fungsi (y adalah fungsi dari x).

x à variabel bebas (independent variable)

y à variabel tak bebas (dependent variable)

Fungsi bernilai tunggal (single-valued) jika, untuk setiap nilai dari y dalam rangenya, terdapat hanya satu nilai dari x.  Y = x + 3

Fungsi bernilai jamak (multivalued)  y = x²

F (x) dibaca “f  fungsi dari x” atau “f dari x”

        Jika fungsi  y =  f (x) adalah sedemikian rupa sehingga untuk setiap y  dalam rangenya terdapat satu dan hanya satu x dalam domainnya sehingga  y = f (x), kita katakan bahwa  f  adalah suatu korespondensi satu-satu.  (fungsinya disebut fungsi bijektif) à ax + by + c = 0

(Sumber :

Ayres, Jr., Frank,  Schmidt, P.A.,2004, Schaum Outlines : Matematika Universitas, Edisi Ketiga, Erlangga, Jakarta)