Помогите пожалуйста!!! 1) tg135*cos(-300)= 2) 8tg 7п/3 * tg 11п/6= 3) 8tg150 * sin(-300)...

Question

Помогите пожалуйста!!!

1) tg135*cos(-300)=

2) 8tg 7п/3 * tg 11п/6=

3) 8tg150 * sin(-300) * cos720=

Answer 1

1) tg135 *cos(-300)=tg(90+45) * cos300=  -ctg45 * cos(360-60)= -1 *cos60= -1/2

2) 8 *tg7π/3 * tg11π/6= 8 * tg(2π+π/3) * tg(2π-π/6)=8*tgπ/3 * (-tgπ/6)= -8*√3 * √3/3= -8

3) 8 tg150* sin(-300) * cos720= 8 tg(180-30) *(-sin(360-60)) * cos(2*360)=

    =8* (-tg30) * sin60 *1=-8 * √3/3 *√3/2= -4

 

 

 

 

 

 

Answer 2

tg135=-1

cos(-300)=0.5

1)-1*0.5=-0.5

8tg7n/3=1.02914

tg11n/6=0.10086

2)1.02914*0.10086=0.1038

8tg150=-4.6188

sin(-300)=0.86603

cos720=1

3)-4.6188*0.86603*1=0.08989