I was too just a couple of weeks ago. So direct variation is the constant way to variables change together. EX:
x y
1 2
2 4
3 6
Direct variation must be in the format b=ka where k is a constant. So the direct variation here could be y=2x. Understand?
Answer: y = v₀tgθx - gx²/2v₀²cos²θ
a = v₀tgθ
b = -g/2v₀²cos²θ
Step-by-step explanation:
x = v₀ₓt
y = v₀y.t - g.t²/2
x = v₀.cosθt → t = x/v₀.cosθ
y = v₀y.t - g.t²/2
v₀y = v₀.senθ
y = v₀senθ.x/v₀cosθ - g/2.(x/v₀cosθ)²
y = v₀.tgθ.x - gx²/2v₀²cos²θ
a = v₀tgθ → constant because v₀ and θ do not change
b = - g/2v₀²cos²θ → constant because v₀, g and θ do not change
C seems to make the most sense, logarithmic and exponential functions are not gradual, and a step function just wouldn't fit in my eyes.
I'm pretty sure that you need to multiply pie times the radius of the circle
