0 < b < 1 a < 0 a > 0q > 0q < 0Table 6.5:The effect ofaandqon an exponential graph when 0 <b< 1.Discovering the characteristics EMA4Y
The standard form of an exponential function isy=abx+q.
Domain and range
Fory=abx+q, the function is defined for all real values ofx. Therefore the domain isfx:x 2 Rg.
The range ofy=abx+qis dependent on the sign ofa.
Fora > 0 :
bx> 0
abx> 0
abx+q > q
f(x)> qTherefore, fora > 0 the range isff(x) :f(x)> qg.
Fora < 0 :
bx> 0
abx< 0
abx+q < q
f(x)< qTherefore, fora < 0 the range isff(x) :f(x)< qg.
Chapter 6. Functions 181