The half-life T1/2 of a radioactive substance is related to its decay constant λ by T1/2=λln(2). If the half-life is 5 years, solve for λ.
Question 3
Skill question
Find the domain, range, and equation of the vertical asymptote of the function y=−2+5ln(x+4).
Question 4
Skill question
Find the x-intercept and y-intercept of the function y=ln(5−x).
Question 5
Skill question
Sketch the graphs of y=log2(x) and y=log2(2x−1)+3. Indicate the vertical asymptotes, x-intercepts, and describe the transformations applied to the parent function.
Question 6
Skill question
Solve for x: log2(x)+log2(3x−2)=4.
Question 7
Skill question
Sketch the graph of y=log0.5(x−3)−1, indicating the vertical asymptote and two key points on the curve.
Question 8
Skill question
Sketch the graphs of y=ln(x) and y=1−ln(x) on the same axes and describe the transformation that maps y=ln(x) to y=1−ln(x).
Question 9
Skill question
Given the logarithmic model y=a+blog10(x), which passes through the points (10,2) and (100,4), find the values of a and b.
Question 10
Skill question
Given the data points (1,0) and (10,15), fit the model y=A+Bln(x). Determine A and B.
Question 11
Skill question
A model for acoustic intensity I in decibels as a function of sound pressure p is I=20log10(p0p). If I=60 when p=0.02Pa, find the reference pressure p0.
Question 12
Skill question
The population P of a bacteria colony is modelled by P(t)=P0+kln(1+t), where t is in hours. If P(0)=100 and P(3)=160, find P0 and k.