Which value of a in the exponential function below would cause the function to stretch? (one-third) superscript x 0.3 0.9 1.0 1.5

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Reflect the point (7,0) across the y-axis

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)