Answer:
The constant of proportionality is 2.
Step-by-step explanation:
In an equation for which we are looking for the constant of proportionality, we use the base form below.
y = kx
In which k is the constant of proportionality. If we use the equation given
y = 2x
We can see k = 2
Answer:

Step-by-step explanation:
Given: sin x + cos x
To change the given trigonometry expression in term of sine only.
Trigonometry identity:-
Expression: 
We get rid of cos x from expression and write as sine form.
Expression:

Hence, The final expression is only sine function.
4
You can just put this into a calculator:
1/2^2 = 0.25
3×5-3 = 12
1^3 = 1
0.25 × 12 + 1 = 4