我有d maths 唔識 大家可唔可以教吓我

2. 試繪畫 y = 1 + cos x的圖像

圖片參考：http://f.imagehost.org/0638/ScreenHunter_01_May_19_21_41.gif


3. 試繪畫 y = -3 + tan x的圖像

圖片參考：http://f.imagehost.org/0762/ScreenHunter_02_May_19_21_46.gif

To tackle this type of problems, you must understand the following principle:
If y = f(x),
then y = f(x) + k is to shift the curve of f(x) up (for + ve k) and down (for -ve k) by k units.
and y = f(x + h) is to shift the curve f(x) to the left ( for +ve h) and to the right (for -ve h) by h units.
For Q2.
y = cos x + 1, now f(x) is cos x.
Based on the above principle, y = cos x + 1 is to shift the y = cos x curve up by 1 unit.
For Q3.
y = tan x - 3. Now f(x) is tan x.
So y = tan x - 3 is to shift the curve y = tan x down by 3 units.

If your calculator (like CASIO fx-5800p) has a function "TABLE",
you may try these method to find out your graphic plots.

1. f(X)=1+cos(X)
Table range
Start: 0
End: 360
Step: 15

the results:-
y0= 1 + cos(0) = 2;
y1= 1 + cos(15) = 1.9659;
y2= 1 + cos(30) = 1.866;
y3, y4,.....................y23; (please calculate accordingly)
y24= 1 + cos(345) = 1.9659;
y25= 1 + cos(360) = 2;

plot (Y) against (X) as accordance with the results above


2. f(X)=-3 + tan(X)
Table range
Start: 0
End: 360
Step: 15

the results:-
y0= -3 + tan(0) = -3;
y1= -3 + tan(15) = -2.732;
y2= -3 + tan(30) = -2.422;
y3, y4,.....................y23; (please calculate accordingly)
y24= -3 + tan(345) = -3.267;
y25= -3 + tan(360) = -3;

again plot (Y) against (X) as accordance with the results above