Answer:
A. v(t) = sin (2πft + π/2) = A cos (2πft)
Step-by-step explanation:
According to trigonometry friction, the following relationship are true;
Sin(A+B) = sinAcosB + cosAsinB
We will be using this relationship to check which option is true.
Wave equation is represented as shown;
y(t) = Asin(2πft±theta)
For positive displacement,
y(t) = Asin(2πft+theta)
If theta = π/2
y(t) = Asin(2πft+π/2)
y(t) = A[ sin 2πftcosπ/2 + cos2πft sin π/2]
Since sinπ/2 = 1 and cos (π/2) = 0
y(t) = A[ sin 2πft (0)+ cos2πft (1)]
y(t) = A[0+ cos2πft]
y(t) = Acos2πft
Hence the expression that is true is expressed as;
v(t) = Asin(2πft+π/2) = Acos2πft
F(-3) = 8
Plug -3 into x and just solve it.
Answer:
84 cm²
Step-by-step explanation:
Surface area of the polyhedron = the sum of the areas of each parts of the net = area of 2 triangles + area of each of the 3 rectangles
Area of 2 triangles:
Base = 4 cm
Height = 3 cm
Area of the 2 triangles = 2(½*base*height)
= 2(½*4*3) = 4*3 = 12 cm²
Area of rectangle with the following dimensions:
Length = 6 cm
Width = 4 cm
Area = length * width = 24 cm²
Area of rectangle with the following dimensions:
Length = 6 cm
Width = 5 cm
Area = length * width = 30 cm²
Area of rectangle with the following dimensions:
Length = 6 cm
Width = 3 cm
Area = length * width = 18 cm²
Surface area of the polyhedron = 12 + 24 + 30 + 18 = 84 cm²
Answer:
ill help
Step-by-step explanation: