B for sure!!!!!!!!!!!!!!!!!!!
Answer:
12/10 simplified is 1 2/10 or 1 1/5
Step-by-step explanation:
We know that
2π/3 radians-------> convert to degrees-----> 2*180/3---> 120°
120°=90°+30°
Part a) Find <span>sin(2π/3)
</span>sin(2π/3)=sin (90°+30°)
we know that
sin (A+B)=sin A*cos B+cos A*sin B
so
sin (90°+30°)=sin 90*cos 30+cos 90*sin 30
sin 90=1
cos 30=√3/2
cos 90=0
sin 30=1/2
sin (90°+30°)=1*√3/2+0*1/2-----> √3/2
the answer part a) is
sin(2π/3)=√3/2
Part b) Find cos (2π/3)
cos (2π/3)=cos (90°+30°)
we know that
cos (A+B)=cos A*cos B-sin A*sin B
so
cos (90°+30°)=cos 90*cos 30-sin 90*sin 30
sin 90=1
cos 30=√3/2
cos 90=0
sin 30=1/2
cos (90°+30°)=0*√3/2-1*1/2----> -1/2
the answer part b) is
cos (2π/3)=-1/2
My common denominator is a 08 cause as I look at the fraction I have a1/2 also falod 1/4 which I had to take of the one to make a 0to subtract to the 2 to give it a 12 to be able to take from the four we have and that is how I came up with a common denominator of 08
for the area of the smaller semicircles
area = 1/2 x 3.142 x 5 x 5
area = 39.275cm²
for the larger circle
area = 1/2 x 3.142 x 10x 10
area= 157.1cm²
but since part of it is out and is replaced again
..total area of shaded part is 157.1cm² + 39.275cm² - 39.275cm²
area =157.1cm²
