Answer:
In the explanation
Step-by-step explanation:
Going to start with the sum identities
sin(x+y)=sin(x)cos(y)+sin(y)cos(x)
cos(x+y)=cos(x)cos(y)-sin(x)sin(y)
sin(x)cos(x+y)=sin(x)cos(x)cos(y)-sin(x)sin(x)sin(y)
cos(x)sin(x+y)=cos(x)sin(x)cos(y)+cos(x)sin(y)cos(x)
Now we are going to take the line there and subtract the line before it from it.
I do also notice that column 1 have cos(y)cos(x)sin(x) in common while column 2 has sin(y) in common.
cos(x)sin(x+y)-sin(x)cos(x+y)
=0+sin(y)[cos^2(x)+sin^2(x)]
=sin(y)(1)
=sin(y)
Answer:
Step-by-step explanation:
Given that the dresser is in shape of a rectangular prism
Note that, a rectangular prism has a shape of a cuboid
So, area of the rectangular prism is same as area of a cuboid
A = (2LB + 2LH + 2BH)
Where
L is length
B is breadth
H is height
Then, given the dimension of the rectangular prism to be
2ft by 2ft by 6ft
Then, you can assume that,
Length L = 2ft
Breadth B = 2ft
Height H = 6ft.
NOTE: you can take you assumption anyhow, there is no standard, you will get the same answer.
Then,
A = (2LB + 2LH + 2BH)
A = (2×2×2 + 2×2×6 + 2×2×6)
A = (8 + 24 + 24)
A = 56 ft²
The total surface area of the dresser is 56ft²