Exponentials and logarithms Flashcards
What does the graph of y=aˣ look like for a>1?
It has an asymptote at y=0 and crosses the y axis at (0,1). It is continually increasing. As x tends to infinity, y tends to infinity, and as x tends to minus infinity, y tends to 0
What does the graph of y=aˣ look like for 0<a<1?
It has an asymptote at y=0 and crosses the y axis at (0,1). It is continually decreasing. As x tends to infinity, y tends to 0, and as x tends to minus infinity, y tends to infinity
How can logₐ(b)=c be rewritten using powers?
aᶜ=b
How can logₐ(bc) be rewritten according to the multiplication law?
logₐ(b)+logₐ(c)
How can logₐ(b/c) be rewritten according to the division law?
logₐ(b)-logₐ(c)
How can logₐ(bᶜ) be rewritten according to the power law?
c*logₐ(b)
How can logₐ(1/b) be rewritten?
-logₐ(b)
How can aᵇ=c be rewritten with b as the subject?
Take logarithms of both sides to give log(aᵇ)=log(c), and then apply the power rule to give b*log(a)=log(c). Then divide by log(a) to give b=log(c)/log(a)
How can logₐ(b) be rewritten in terms of logarithms with base r according to the change of base rule?
logᵣ(b)/logᵣ(a)
How can 1/logₐ(x) be rewritten?
logₓ(a)