Notebook cost $1.20 each. this weekend they will be on sale for $0.80. what percentage is the sale

What is the range of the data below? .8090100

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

Hardest math question of all time can you solve the equation. check for extraneous solutions.9∣9-8x∣ = 2x+3