Maths - Exponentials

2021-02-01
3 min read

See Also

Flashcards

$$y = a^x \ y = a^{-x}$$ What is true about these two graphs??

They are reflections of each other in the $y$-axis.

$$y = a^x$$ What is the $y$-intercept of this graph??

$$ 1 $$

$$\log_a b = c$$ If this is true, what is also true??

$$ a^c = b $$

$$3^x = 9$$ What would you do to both sides to make $x$ the subject??

$$ \log_3 $$

$$\log_a a$$ What is this equal to??

$$ 1 $$

$$\log_a 1$$ What is this equal to??

$$ 0 $$

$$\log_a \frac{1}{a}$$ What is this equal to??

$$ -1 $$

$$\log_a m + \log_a n$$ How could you rewrite this??

$$ \log_a mn $$

$$\log_a mn$$ How could you rewrite this??

$$ \log_a m + \log_b n $$

$$\log_a m - \log_b n$$ How could you rewrite this??

$$ \log_a \left(\frac{m}{n}\right) $$

$$\log_a \left(\frac{m}{n}\right)$$ How could you rewrite this??

$$ \log_a m - \log_b n $$

$$\log_a x^n$$ How could you rewrite this??

$$ n \log_a x $$

$$n \log_a x$$ How could you rewrite this??

$$ \log_a x^n $$

$$\log_a \left(\frac{1}{y}\right)$$ How could you rewrite this??

$$ -\log_a y $$

$$-\log_a y$$ How could you rewrite this??

$$ \log_a \left(\frac{1}{y}\right) $$

$$2\log a$$ How could you rewrite this??

$$ \log a^2 $$

$$\frac{1}{2} \log a$$ How could you rewrite this??

$$ \log\sqrt{a} $$

2021-02-02

Why does $\log_a x$ always cut the $x$-axis at $1$??

Because $a^0$ always equals $1$.

Why does the graph of $\log_a x$ get steeper the smaller value of $a$??

Because you have the raise $a$ to a higher power to get the same result.

What is $10^{\log_{10} x}$??

$$ x $$

For what value of $a^x$ does the ratio between the gradient a point and the value of the point equal $1$??

$$ e $$

$$\frac{dy}{dx} \div y : 2^x \to 0.7, 3^x \to 1.1$$ What value base do you need to raise to the power of $x$ for it to equal $1$??

$$ e $$

2021-05-13

What’s the general exponential model for a population $p$ with a initial population $a$, a “growth rate” $b$ and a time $t$??

$$ p = ab^t $$

What do you get if you simlify the $\log_10$ of both sides of $p = ab^t$??

$$ \log_{10} p = t\log_{10} b + \log_{10} a $$

What should you plot for a time $t$ and a poopulation size $p$ to see if the population grows exponentially??

$t$ against $\log_{10}(p)$.

What is the gradient of a $t$ against $\log_10(p)$ graph equal to??

$$ \log_{10}(b) $$

2021-10-12

What is the first stage of solving $$3^{2x + 1} = 4^{3x}$$??

Taking any $\log$ of both sides.

How can you simplify this $$\ln(3^{2x+1}) = \ln(4^{3x})$$??

Using the power rule

$$ (2x+1)\ln(3) = (3x)\ln(3) $$


Metadata
date: 2021-02-01 09:59
tags:
- '@?maths'
- '@?public'
- '@?further-maths'
title: Maths - Exponentials