1) 3sin²π:2-4tg²π:4-3cos²π:6+3ctg²π:2

2) tg5π:4*sinπ:3-cos7π:6*sin3π:2

3) sinα=3:4,0≤α≤π:2

4) ctgα=2:3,π≤α≤3π:2

5) ctgα-cosα-1:sinα

6) (sinβ*ctgβ) ² + (cosβ*tgβ) 2

1) 3*1²-4*1²-3 * (√3/2) ²+3*0²=3-4-2,25+0=-3,25

2) 1*√3/2 - (-√3/2) * (-1) = √/2-√3/2=0

3) sina=3/4,0≤a≤π/2

a=arcsin3/4

4) ctga=2/3,π≤a3π/2

a=π+arcctg2/3

5) ctga - (cosa-1) / sina=cosa/sina - (cosa - 1) / sina=

= (cosa-cosa+1) / sina=1/sina

6) (sinb*ctgb) ² + (cosb*tgb) ² = (sinb*cosb/sinb) ² + (cosb*sinb/cosb) ²=

=cos²b+sin²b=1