7*√33*sin(arccos 4/7)

Question

7*√33*sin(arccos 4/7)

Answer 1

1)sin(arccos(4/7))

sin(arcsin(4/7))=4/7

 

cos^2A=1-sin^2A

 

cos^2(4/7)=1-(4/7)^2=33/49

cos(4/7)=sqrt(33)/7

 

sin(arccos(4/7))= sqrt(33)/7

2)7*√33*sqrt(33)/7=33