Question

Which graph represents exponential decay?

On a coordinate plane, a straight line has a negative slope.
On a coordinate plane, a graph starts at (negative 2, 0) and curves up and to the right into quadrant 1.
On a coordinate plane, a graph approaches y = 0 in quadrant 1 and curves up into quadrant 2.
On a coordinate plane, a graph approaches y = 0 in quadrant 2 and curves up into quadrant 1.

Answer 1

The third description: "a graph approaches y = 0 in quadrant 1 and curves up into quadrant 2."

Reason: exponential decay (y = a b^x with 0<b<1, a>0) stays positive, falls toward 0 as x → +∞ (so it approaches y=0 on the right/in quadrant I) and increases without bound as x → −∞ (so it rises into quadrant II). The other options are linear, cross the x-axis, or show growth.