John's age 4 years ago, if he will be y years old in 5 years

To find the extreme values of a function f(x. y) on a curve x-x(t), y y(t), treat f as a function of the single variable t and use the chain rule to find where df/dt is zero. in any other single-variable case, the extreme values of f are then found among the values at the critical points (points where df/dt is zero or fails to exist), and endpoints of the parameter domain. find the absolute maximum and minimum values of the following function on the given curves. use the parametric equations x=2cos t, y 2 sin t functions: curves: i) the semicircle x4,y20 i) the quarter circle x2+y-4, x20, y20 b, g(x, y)=xy

Tim open up a new saving account with a $50 deposit and plant to deposit $20 per week into the same account. write an expression to represent the total amount in his savings account.

(-y to the power of 2 - 4y- to the power of 2 -6 y +3)