Use photo math it works great
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
A. A Parsec
A parsec is a unit of distance used to measure huge distances (as in solar system measurements)
a function is a relationship or expression involving one or more variables. It has a set of input and outputs. Each input has only one output. The function is the description of how the inputs relate to the output.
D. he can access it by taking it out of his account
