Solving Exponential Equations Graphically
Given the function f(x)=170(1.07)x\displaystyle {f{{\left({x}\right)}}}={170}{\left({1.07}\right)}^{{x}} find x when f(x)=255\displaystyle {f{{\left({x}\right)}}}={255} using your graphing calculator. Then follow the steps below to show the intersection graph on the computer. [Hint: Use the following window on your graphing calculator: Xmin = -5, Xmax = 8, Ymin = 120, Ymax = 265]
  1. Write the point of intersection as an ordered pair below. Round the value of x\displaystyle {x} to two decimal places.
  2. Use the Line Tool to draw the Horizontal Line y=255\displaystyle {y}={255}.
  3. Use the Exponential Tool to draw f(x)=170(1.07)x\displaystyle {f{{\left({x}\right)}}}={170}{\left({1.07}\right)}^{{x}}.
  4. Use the Point Tool to identify the point of intersection.
170(1.07)x=255\displaystyle {170}{\left({1.07}\right)}^{{x}}={255}

Point of Intersection:

Clear All Draw: LineExponentialDot