204 results authored by Bill Foster - search across all users.
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Question in Bill's workspace
The derivative of $\displaystyle \frac{ax^2+b}{cx^2+d}$ is $\displaystyle \frac{g(x)}{(cx^2+d)^2}$. Find $g(x)$.
Contains a video solving a similar quotient rule example. Although does not explicitly find $g(x)$ as asked in the question, but this is obvious.
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Question in Bill's workspace
Find the gradient of $ \displaystyle ax^b+\frac{c}{x^{d}}+f$ at $x=a$
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Question in Bill's workspace
Find the stationary points of a cubic which has 2 turning points.
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Question in Bill's workspace
Examples on differentiation using the quotient rule and chain rule.
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Question in Bill's workspace
Differentiate $\displaystyle ax^b, ax^b+cx^{1/d}, \frac{a}{x^{1/c}}+\frac{b}{x^{-1/d}}+c$ with respect to $x$.
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Question in Bill's workspace
Differentiate $f(x)=x^{m}\sin(ax+b) e^{nx}$.
The answer is of the form:
$\displaystyle \frac{df}{dx}= x^{m-1}e^{nx}g(x)$ for a function $g(x)$.Find $g(x)$.
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Question in Bill's workspace
Application of the Poisson distribution given expected number of events per interval.
Finding probabilities using the Poisson distribution.
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Question in Bill's workspace
Application of the binomial distribution given probabilities of success of an event.
Finding probabilities using the binomial distribution.
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Question in Bill's workspace
Given a random variable $X$ normally distributed as $\operatorname{N}(m,\sigma^2)$ find probabilities $P(X \gt a),\; a \gt m;\;\;P(X \lt b),\;b \lt m$.
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Question in Bill's workspace
Exercise using a given uniform distribution $X$, calculating the expectation and variance. Also finding $P(X \le a)$ for a given value $a$.
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Question in Bill's workspace
Question on the exponential distribution involving a time intervals and arrivals application, finding expectation and variance. Also finding the probability that a time interval between arrivals is less than a given period. All parameters and times randomised.
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Question in Bill's workspace
Divide $ f(x)=x ^ 4 + ax ^ 3 + bx^2 + cx+d$ by $g(x)=x^2+p $ so that:
$\displaystyle \frac{f(x)}{g(x)}=q(x)+\frac{r(x)}{g(x)}$ -
Question in Bill's workspace
Dividing a cubic polynomial by a linear polynomial. Find quotient and remainder.
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Question in Bill's workspace
Split $\displaystyle \frac{ax+b}{(cx + d)(px+q)}$ into partial fractions.
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Question in Bill's workspace
Questions testing addition, subtraction, multiplication of numerical fractions and reduction to lowest terms. They also test BIDMAS in the context of fractions.
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Question in Bill's workspace
Reducing fractions to their lowest form by cancelling common factors in the numerator and denominator. There are 4 questions.
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Question in Bill's workspace
Add/subtract fractions and reduce to lowest form.
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Question in Bill's workspace
Questions testing understanding of numerators and denominators of numerical fractions, and reduction to lowest terms.
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Question in Bill's workspace
Find $\displaystyle \frac{a} {b + \frac{c}{d}}$ as a single fraction in the form $\displaystyle \frac{p}{q}$ for integers $p$ and $q$.
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Question in Bill's workspace
Questions testing understanding of numerators and denominators of numerical fractions.
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Question in Bill's workspace
Questions testing understanding of numerators and denominators of numerical fractions, and reduction to lowest terms.
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Question in Bill's workspace
Given sample data find mean, standard deviation, median, interquartile range.
Note that there are different versions of the upper and lower quartiles, so you may want to include your own versions - see the user defined functions in the question.
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Question in Bill's workspace
Given a table of the number of days in which sales were between £x1000 and £(x+1)1000 find the relative percentage frequencies of these volume of sales.
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Question in Bill's workspace
Deciding whether or not three sampling methods are simple random sampling, stratified sampling, systematic or judgemental sampling. Also whether or not the method of selection is random, quasi-random or non-random.
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Question in Bill's workspace
Choosing whether given random variables are qualitiative or quantitative.
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Question in Bill's workspace
Solve for $x$ each of the following equations: $n^{ax+b}=m^{cx}$ and $p^{rx^2}=q^{sx}$.
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Question in Bill's workspace
Express $\log_a(x^{c}y^{d})$ in terms of $\log_a(x)$ and $\log_a(y)$. Find $q(x)$ such that $\frac{f}{g}\log_a(x)+\log_a(rx+s)-\log_a(x^{1/t})=\log_a(q(x))$.
There is a video included explaining the rules of logarithms by going through simplification of logs of numbers rather than algebraic expressions.
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Question in Bill's workspace
Solve for $x$: $\log(ax+b)-\log(cx+d)=s$
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Question in Bill's workspace
Solve for $x$: $\displaystyle 2\log_{a}(x+b)- \log_{a}(x+c)=d$.
Make sure that your choice is a solution by substituting back into the equation.
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Question in Bill's workspace
Solve for $x$: $\log_{a}(x+b)- \log_{a}(x+c)=d$