Always
a=b
subtract c from each side
a-c = b-c
3/4 + 1/12 = 10/12 and then you simplify it and get 5/6 as your final answer.
If it is just the decimal 3.1415 then it is rational. If it is pi it is irrational
Dy/dx = (dy/dt) / (dx/dt)
dy/dt = 2cos(2t)
dx/dt = -2sin(2t)
dy/dx = 2cos(2t)/-2sin(2t) = -cot(2t)
d^y/dx^2 = d(-1/tan(2t))/dx = (tan(2t) * 0 - (-1)*2sec^2(2t))/tan^2(2t) = 2sec^2(2t)/tan^2(2t) = 2csc^2 (2t)
It is .21 or 21 cents for each pound.
