Ask A Scientist Mathematics Archive

Author:      mike f frain
When in the world will you need to know the formula for a quadratic equa-
tion?  It seems unlikely you need to know  ax^2 + bx + c = 0  anytime in
your life.

Response #:  1 of 2
Author:      asmith
Well, number 1, you need to know that to do a lot of higher mathematics.  It
is basic to a lot of stuff in complex arithmetic and trigonometry.  (half--
angle formulas and the like).  Number 2 it comes up an awful lot in physics,
whenever you have a variable that has a quadratic dependency that you need
to solve for - a simple example is motion under acceleration, where if you
want to know the time at which a falling object will hit the ground, you
need to solve a quadratic equation.

Response #:  2 of 2
Author:      jlu
Here is a problem that most physics students have to do.  It requires use of
quadratics.  A one pound brick is dropped on a scale from a height of one
inch.  The maximum reading of the scale is 5 pounds, and if a heavier weight
is placed on the scale, it will break.  Will the scale break?  The scale is
a spring scale, and the spring deflects 1/32 of an inch under a steady one
pound load.