Product-to-Sum

[nycmathguy]

Section 5.5

 

[MathLover1]

50. correct but you need to finish it

=-7/2 (sin(-8β) - sin(-2β ))

=-7/2 (-2sin(β) cos(β) (2 cos(2 β) + 1) (-2 cos(2 β) + 2 cos(4 β) + 1))

=7 sin(β) cos(β) (2 cos(2 β) + 1) (-2 cos(2 β) + 2 cos(4 β) + 1)

52. also need to finish

(1/2) (sin(2x) + sin(2 y))

sin(2x) =2sin(x) cos(x)
sin(2 y)=2sin(y) cos(y)

=(1/2) (2sin(x) cos(x) +2sin(y) cos(y))

=(1/2)*2 (sin(x) cos(x) +sin(y) cos(y))

=sin(x) cos(x) +sin(y) cos(y)

 

[nycmathguy]

50. correct but you need to finish it

=-7/2 (sin(-8β) - sin(-2β ))

=-7/2 (-2sin(β) cos(β) (2 cos(2 β) + 1) (-2 cos(2 β) + 2 cos(4 β) + 1))

=7 sin(β) cos(β) (2 cos(2 β) + 1) (-2 cos(2 β) + 2 cos(4 β) + 1)

52. also need to finish

(1/2) (sin(2x) + sin(2 y))

sin(2x) =2sin(x) cos(x)
sin(2 y)=2sin(y) cos(y)

=(1/2) (2sin(x) cos(x) +2sin(y) cos(y))

=(1/2)*2 (sin(x) cos(x) +sin(y) cos(y))

=sin(x) cos(x) +sin(y) cos(y)

Correct but incomplete on my part. In that case, I will work on 49 and 51. Look for my work tomorrow.

P. S. I got tested for COVID-19 yesterday after experiencing flu-like symptoms. My boss gave me two nights off. I can do math Monday and Tuesday this week.

 

[MathLover1]

I hope it's flu.

 

[nycmathguy]

I hope it's flu.

I hope so. I'll let you know.

 

[nycmathguy]

I hope it's flu.

 

[MathLover1]

correct

 

[nycmathguy]

correct

We can move pass this topic for now.