Group a 1.4- 1

1. Draw a chart of the following functions:

( 1)y= 1-sin x，x∈[0，2π]

(2)y=3cos x+ 1，x∈[0，2π]

Group b 1.4- 1

1. According to the images of sine function and cosine function, write a set of x containing the following inequalities:

(1)sin x≥√3/2(x∈R)√3/2 is a semi-radical number three, and the denominator has no radical number.

(2)√2+2cos x≥0(x∈R)