Exponentials and logarithms Flashcards
1
Q
loga b meaning
A
a to the power of what = b
2
Q
log combinations
A
log a + log b = logab
log a - log b = log a/b
x log a = log a^x
3
Q
ln (x)
A
same as saying log e (x)
4
Q
differentiation of x
A
dy/ dx of e^2x = 2e^2x
x can be anything else e.g dy/dt of 4e^3t = 12e^3t
5
Q
linearising exponentials
A
y = ab^x
log y = log a + x log b
as y = mx + c
so draw a graph of log y against x
log a is y intercept and log b is gradient
for a do intercept^10
for b do gradient ^ 10
6
Q
linearising polynomials
A
y = ax^b
log y = log a + t log x
y = mx + c so
draw graph of log y against log x
log a is y intercept and b is gradient
a = 10^intercept and b is m